Class PGconn
In: ext/pg.c
Parent: Object

The class to access PostgreSQL RDBMS, based on the libpq interface, provides convenient OO methods to interact with PostgreSQL.

For example, to send query to the database on the localhost:

   require 'pg'
   conn = PGconn.open(:dbname => 'test')
   res = conn.exec('SELECT $1 AS a, $2 AS b, $3 AS c',[1, 2, nil])
   # Equivalent to:
   #  res  = conn.exec('SELECT 1 AS a, 2 AS b, NULL AS c')

See the PGresult class for information on working with the results of a query.

Methods

async_exec   async_query   backend_pid   block   cancel   close   conndefaults   conndefaults   connect_poll   connect_start   connection_needs_password   connection_used_password   consume_input   db   describe_portal   describe_prepared   encrypt_password   error_message   escape   escape_bytea   escape_bytea   escape_string   escape_string   exec   exec_prepared   external_encoding   finish   flush   get_client_encoding   get_copy_data   get_last_result   get_result   host   internal_encoding   internal_encoding=   is_busy   isnonblocking   isthreadsafe   lo_close   lo_creat   lo_create   lo_export   lo_import   lo_lseek   lo_open   lo_read   lo_seek   lo_tell   lo_truncate   lo_unlink   lo_write   loclose   locreat   locreate   loexport   loimport   lolseek   loopen   loread   loseek   lotell   lotruncate   lounlink   lowrite   make_empty_pgresult   new   nonblocking?   notifies   notifies_wait   options   parameter_status   pass   port   prepare   protocol_version   put_copy_data   put_copy_end   query   quote_ident   quote_ident   reset   reset_poll   reset_start   send_describe_portal   send_describe_prepared   send_prepare   send_query   send_query_prepared   server_version   set_client_encoding   set_error_verbosity   set_notice_processor   set_notice_receiver   setnonblocking   socket   status   trace   transaction   transaction_status   tty   unescape_bytea   unescape_bytea   untrace   user   wait_for_notify  

Constants

VERSION = rb_str_new2(VERSION)   Library version
CONNECTION_OK = INT2FIX(CONNECTION_OK)   Connection succeeded
CONNECTION_BAD = INT2FIX(CONNECTION_BAD)   Connection failed
CONNECTION_STARTED = INT2FIX(CONNECTION_STARTED)   Waiting for connection to be made.
CONNECTION_MADE = INT2FIX(CONNECTION_MADE)   Connection OK; waiting to send.
CONNECTION_AWAITING_RESPONSE = INT2FIX(CONNECTION_AWAITING_RESPONSE)   Waiting for a response from the server.
CONNECTION_AUTH_OK = INT2FIX(CONNECTION_AUTH_OK)   Received authentication; waiting for backend start-up to finish.
CONNECTION_SSL_STARTUP = INT2FIX(CONNECTION_SSL_STARTUP)   Negotiating SSL encryption.
CONNECTION_SETENV = INT2FIX(CONNECTION_SETENV)   Negotiating environment-driven parameter settings.
PGRES_POLLING_READING = INT2FIX(PGRES_POLLING_READING)   Async connection is waiting to read
PGRES_POLLING_WRITING = INT2FIX(PGRES_POLLING_WRITING)   Async connection is waiting to write
PGRES_POLLING_FAILED = INT2FIX(PGRES_POLLING_FAILED)   Async connection failed or was reset
PGRES_POLLING_OK = INT2FIX(PGRES_POLLING_OK)   Async connection succeeded
PQTRANS_IDLE = INT2FIX(PQTRANS_IDLE)   Transaction is currently idle (transaction_status)
PQTRANS_ACTIVE = INT2FIX(PQTRANS_ACTIVE)   Transaction is currently active; query has been sent to the server, but not yet completed. (transaction_status)
PQTRANS_INTRANS = INT2FIX(PQTRANS_INTRANS)   Transaction is currently idle, in a valid transaction block (transaction_status)
PQTRANS_INERROR = INT2FIX(PQTRANS_INERROR)   Transaction is currently idle, in a failed transaction block (transaction_status)
PQTRANS_UNKNOWN = INT2FIX(PQTRANS_UNKNOWN)   Transaction‘s connection is bad (transaction_status)
PQERRORS_TERSE = INT2FIX(PQERRORS_TERSE)   Terse error verbosity level (set_error_verbosity)
PQERRORS_DEFAULT = INT2FIX(PQERRORS_DEFAULT)   Default error verbosity level (set_error_verbosity)
PQERRORS_VERBOSE = INT2FIX(PQERRORS_VERBOSE)   Verbose error verbosity level (set_error_verbosity)
INV_WRITE = INT2FIX(INV_WRITE)   Flag for lo_creat, lo_open — open for writing
INV_READ = INT2FIX(INV_READ)   Flag for lo_creat, lo_open — open for reading
SEEK_SET = INT2FIX(SEEK_SET)   Flag for lo_lseek — seek from object start
SEEK_CUR = INT2FIX(SEEK_CUR)   Flag for lo_lseek — seek from current position
SEEK_END = INT2FIX(SEEK_END)   Flag for lo_lseek — seek from object end

Public Class methods

Returns an array of hashes. Each hash has the keys:

+:keyword+
the name of the option
+:envvar+
the environment variable to fall back to
+:compiled+
the compiled in option as a secondary fallback
+:val+
the option‘s current value, or nil if not known
+:label+
the label for the field
+:dispchar+
"" for normal, "D" for debug, and "*" for password
+:dispsize+
field size

[Source]

/*
 * call-seq:
 *    PGconn.conndefaults() -> Array
 *
 * Returns an array of hashes. Each hash has the keys:
 * [+:keyword+]
 *   the name of the option
 * [+:envvar+]
 *   the environment variable to fall back to
 * [+:compiled+]
 *   the compiled in option as a secondary fallback
 * [+:val+]
 *   the option's current value, or +nil+ if not known
 * [+:label+]
 *   the label for the field
 * [+:dispchar+]
 *   "" for normal, "D" for debug, and "*" for password
 * [+:dispsize+]
 *   field size
 */
static VALUE
pgconn_s_conndefaults(VALUE self)
{
        PQconninfoOption *options = PQconndefaults();
        VALUE ary = rb_ary_new();
        VALUE hash;
        int i = 0;

        for(i = 0; options[i].keyword != NULL; i++) {
                hash = rb_hash_new();
                if(options[i].keyword)
                        rb_hash_aset(hash, ID2SYM(rb_intern("keyword")), 
                                rb_str_new2(options[i].keyword));
                if(options[i].envvar)
                        rb_hash_aset(hash, ID2SYM(rb_intern("envvar")), 
                                rb_str_new2(options[i].envvar));
                if(options[i].compiled)
                        rb_hash_aset(hash, ID2SYM(rb_intern("compiled")), 
                                rb_str_new2(options[i].compiled));
                if(options[i].val)
                        rb_hash_aset(hash, ID2SYM(rb_intern("val")), 
                                rb_str_new2(options[i].val));
                if(options[i].label)
                        rb_hash_aset(hash, ID2SYM(rb_intern("label")), 
                                rb_str_new2(options[i].label));
                if(options[i].dispchar)
                        rb_hash_aset(hash, ID2SYM(rb_intern("dispchar")), 
                                rb_str_new2(options[i].dispchar));
                rb_hash_aset(hash, ID2SYM(rb_intern("dispsize")), 
                        INT2NUM(options[i].dispsize));
                rb_ary_push(ary, hash);
        }
        PQconninfoFree(options);
        return ary;
}

This is an asynchronous version of PGconn.connect().

Use PGconn#connect_poll to poll the status of the connection.

NOTE: this does not set the connection‘s client_encoding for you if Encoding.default_internal is set. To set it after the connection is established, call PGconn#internal_encoding=. You can also set it automatically by setting ENV[‘PGCLIENTENCODING’], or include the ‘options’ connection parameter.

[Source]

/*
 * call-seq:
 *    PGconn.connect_start(connection_hash)       -> PGconn
 *    PGconn.connect_start(connection_string)     -> PGconn
 *    PGconn.connect_start(host, port, options, tty, dbname, login, password) ->  PGconn
 *
 * This is an asynchronous version of PGconn.connect().
 *
 * Use PGconn#connect_poll to poll the status of the connection.
 *
 * NOTE: this does *not* set the connection's +client_encoding+ for you if 
 * Encoding.default_internal is set. To set it after the connection is established, 
 * call PGconn#internal_encoding=. You can also set it automatically by setting 
 * ENV['PGCLIENTENCODING'], or include the 'options' connection parameter.
 * 
 */
static VALUE
pgconn_s_connect_start(int argc, VALUE *argv, VALUE self)
{
        PGconn *conn = NULL;
        VALUE rb_conn;
        VALUE conninfo;
        VALUE error;

        /*
         * PGconn.connect_start must act as both alloc() and initialize()
         * because it is not invoked by calling new().
         */
        rb_conn = pgconn_alloc(rb_cPGconn);

        conninfo = rb_funcall2( rb_cPGconn, rb_intern("parse_connect_args"), argc, argv );
        conn = PQconnectStart(StringValuePtr(conninfo));

        if(conn == NULL)
                rb_raise(rb_ePGError, "PQconnectStart() unable to allocate structure");
        if (PQstatus(conn) == CONNECTION_BAD) {
                error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn));
                rb_iv_set(error, "@connection", self);
                rb_exc_raise(error);
        }

        Check_Type(rb_conn, T_DATA);
        DATA_PTR(rb_conn) = conn;

        if (rb_block_given_p()) {
                return rb_ensure(rb_yield, self, pgconn_finish, self);
        }
        return rb_conn;
}

This function is intended to be used by client applications that send commands like: +ALTER USER joe PASSWORD ‘pwd’+. The arguments are the cleartext password, and the SQL name of the user it is for.

Return value is the encrypted password.

[Source]

/*
 * call-seq:
 *    PGconn.encrypt_password( password, username ) -> String
 *
 * This function is intended to be used by client applications that
 * send commands like: +ALTER USER joe PASSWORD 'pwd'+.
 * The arguments are the cleartext password, and the SQL name 
 * of the user it is for.
 *
 * Return value is the encrypted password.
 */
static VALUE
pgconn_s_encrypt_password(VALUE self, VALUE password, VALUE username)
{
        char *encrypted = NULL;
        VALUE rval = Qnil;

        Check_Type(password, T_STRING);
        Check_Type(username, T_STRING);

        encrypted = PQencryptPassword(StringValuePtr(password), StringValuePtr(username));
        rval = rb_str_new2( encrypted );
        PQfreemem( encrypted );

        OBJ_INFECT( rval, password );
        OBJ_INFECT( rval, username );

        return rval;
}

Connection instance method for versions of 8.1 and higher of libpq uses PQescapeByteaConn, which is safer. Avoid calling as a class method, the class method uses the deprecated PQescapeBytea() API function.

Use the instance method version of this function, it is safer than the class method.

Escapes binary data for use within an SQL command with the type bytea.

Certain byte values must be escaped (but all byte values may be escaped) when used as part of a bytea literal in an SQL statement. In general, to escape a byte, it is converted into the three digit octal number equal to the octet value, and preceded by two backslashes. The single quote (’) and backslash (\) characters have special alternative escape sequences. escape_bytea performs this operation, escaping only the minimally required bytes.

Consider using exec_params, which avoids the need for passing values inside of SQL commands.

[Source]

/*
 * call-seq:
 *   conn.escape_bytea( string ) -> String 
 *
 * Connection instance method for versions of 8.1 and higher of libpq
 * uses PQescapeByteaConn, which is safer. Avoid calling as a class method,
 * the class method uses the deprecated PQescapeBytea() API function.
 *
 * Use the instance method version of this function, it is safer than the
 * class method.
 *
 * Escapes binary data for use within an SQL command with the type +bytea+.
 * 
 * Certain byte values must be escaped (but all byte values may be escaped)
 * when used as part of a +bytea+ literal in an SQL statement. In general, to
 * escape a byte, it is converted into the three digit octal number equal to
 * the octet value, and preceded by two backslashes. The single quote (') and
 * backslash (\) characters have special alternative escape sequences.
 * #escape_bytea performs this operation, escaping only the minimally required 
 * bytes.
 * 
 * Consider using exec_params, which avoids the need for passing values inside of 
 * SQL commands.
 */
static VALUE
pgconn_s_escape_bytea(VALUE self, VALUE str)
{
        unsigned char *from, *to;
        size_t from_len, to_len;
        VALUE ret;

        Check_Type(str, T_STRING);
        from      = (unsigned char*)RSTRING_PTR(str);
        from_len  = RSTRING_LEN(str);

        if(rb_obj_class(self) == rb_cPGconn) {
                to = PQescapeByteaConn(get_pgconn(self), from, from_len, &to_len);
        } else {
                to = PQescapeBytea( from, from_len, &to_len);
        }

        ret = rb_str_new((char*)to, to_len - 1);
        OBJ_INFECT(ret, str);
        PQfreemem(to);
        return ret;
}

Connection instance method for versions of 8.1 and higher of libpq uses PQescapeStringConn, which is safer. Avoid calling as a class method, the class method uses the deprecated PQescapeString() API function.

Returns a SQL-safe version of the String str. This is the preferred way to make strings safe for inclusion in SQL queries.

Consider using exec_params, which avoids the need for passing values inside of SQL commands.

Encoding of escaped string will be equal to client encoding of connection.

[Source]

/*
 * call-seq:
 *    conn.escape_string( str ) -> String
 *
 * Connection instance method for versions of 8.1 and higher of libpq
 * uses PQescapeStringConn, which is safer. Avoid calling as a class method,
 * the class method uses the deprecated PQescapeString() API function.
 * 
 * Returns a SQL-safe version of the String _str_.
 * This is the preferred way to make strings safe for inclusion in 
 * SQL queries.
 * 
 * Consider using exec_params, which avoids the need for passing values 
 * inside of SQL commands.
 *
 * Encoding of escaped string will be equal to client encoding of connection.
 */
static VALUE
pgconn_s_escape(VALUE self, VALUE string)
{
        char *escaped;
        int size,error;
        VALUE result;
#ifdef M17N_SUPPORTED   
        rb_encoding* enc;
#endif

        Check_Type(string, T_STRING);

        escaped = ALLOC_N(char, RSTRING_LEN(string) * 2 + 1);
        if(rb_obj_class(self) == rb_cPGconn) {
                size = PQescapeStringConn(get_pgconn(self), escaped, 
                        RSTRING_PTR(string), RSTRING_LEN(string), &error);
                if(error) {
                        xfree(escaped);
                        rb_raise(rb_ePGError, "%s", PQerrorMessage(get_pgconn(self)));
                }
        } else {
                size = PQescapeString(escaped, RSTRING_PTR(string),
                        RSTRING_LEN(string));
        }
        result = rb_str_new(escaped, size);
        xfree(escaped);
        OBJ_INFECT(result, string);

#ifdef M17N_SUPPORTED
        if(rb_obj_class(self) == rb_cPGconn) {
                enc = pgconn_get_client_encoding_as_rb_encoding(get_pgconn(self));
        } else {
                enc = rb_enc_get(string);
        }
        rb_enc_associate(result, enc);
#endif

        return result;
}

Returns true if libpq is thread safe, false otherwise.

[Source]

/*
 * call-seq:
 *    PGconn.isthreadsafe() -> Boolean
 *
 * Returns +true+ if libpq is thread safe, +false+ otherwise.
 */
static VALUE
pgconn_s_isthreadsafe(VALUE self)
{
        return PQisthreadsafe() ? Qtrue : Qfalse;
}

Create a connection to the specified server.

host
server hostname
hostaddr
server address (avoids hostname lookup, overrides host)
port
server port number
dbname
connecting database name
user
login user name
password
login password
connect_timeout
maximum time to wait for connection to succeed
options
backend options
tty
(ignored in newer versions of PostgreSQL)
sslmode
(disable|allow|prefer|require)
krbsrvname
kerberos service name
gsslib
GSS library to use for GSSAPI authentication
service
service name to use for additional parameters

Examples:

  # Connect using all defaults
  PGconn.connect

  # As a Hash
  PGconn.connect( :dbname => 'test', :port => 5432 )

  # As a String
  PGconn.connect( "dbname=test port=5432" )

  # As an Array
  PGconn.connect( nil, 5432, nil, nil, 'test', nil, nil )

If the Ruby default internal encoding is set (i.e., Encoding.default_internal != nil), the connection will have its client_encoding set accordingly.

Raises a PGError if the connection fails.

[Source]

/*
 * Document-method: new
 *
 * call-seq:
 *    PGconn.new -> PGconn
 *    PGconn.new(connection_hash) -> PGconn
 *    PGconn.new(connection_string) -> PGconn
 *    PGconn.new(host, port, options, tty, dbname, user, password) ->  PGconn
 * 
 * Create a connection to the specified server.
 * 
 * [+host+]
 *   server hostname
 * [+hostaddr+]
 *   server address (avoids hostname lookup, overrides +host+)
 * [+port+]
 *   server port number
 * [+dbname+]
 *   connecting database name
 * [+user+]
 *   login user name
 * [+password+]
 *   login password
 * [+connect_timeout+]
 *   maximum time to wait for connection to succeed
 * [+options+]
 *   backend options
 * [+tty+]
 *   (ignored in newer versions of PostgreSQL)
 * [+sslmode+]
 *   (disable|allow|prefer|require)
 * [+krbsrvname+]
 *   kerberos service name
 * [+gsslib+]
 *   GSS library to use for GSSAPI authentication
 * [+service+]
 *   service name to use for additional parameters
 * 
 * Examples:
 * 
 *   # Connect using all defaults
 *   PGconn.connect
 *
 *   # As a Hash
 *   PGconn.connect( :dbname => 'test', :port => 5432 )
 *   
 *   # As a String
 *   PGconn.connect( "dbname=test port=5432" )
 *   
 *   # As an Array
 *   PGconn.connect( nil, 5432, nil, nil, 'test', nil, nil )
 *  
 * If the Ruby default internal encoding is set (i.e., Encoding.default_internal != nil), the
 * connection will have its +client_encoding+ set accordingly.
 * 
 * Raises a PGError if the connection fails.
 */
static VALUE
pgconn_init(int argc, VALUE *argv, VALUE self)
{
        PGconn *conn = NULL;
        VALUE conninfo;
        VALUE error;
#ifdef M17N_SUPPORTED   
        rb_encoding *enc;
        const char *encname;
#endif

        conninfo = rb_funcall2( rb_cPGconn, rb_intern("parse_connect_args"), argc, argv );
        conn = PQconnectdb(StringValuePtr(conninfo));

        if(conn == NULL)
                rb_raise(rb_ePGError, "PQconnectStart() unable to allocate structure");

        Check_Type(self, T_DATA);
        DATA_PTR(self) = conn;

        if (PQstatus(conn) == CONNECTION_BAD) {
                error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn));
                rb_iv_set(error, "@connection", self);
                rb_exc_raise(error);
        }

#ifdef M17N_SUPPORTED
        /* If Ruby has its Encoding.default_internal set, set PostgreSQL's client_encoding 
         * to match */
        if (( enc = rb_default_internal_encoding() )) {
                encname = pgconn_get_rb_encoding_as_pg_encname( enc );
                if ( PQsetClientEncoding(conn, encname) != 0 )
                        rb_warn( "Failed to set the default_internal encoding to %s: '%s'",
                                 encname, PQerrorMessage(conn) );
        }
#endif

        if (rb_block_given_p()) {
                return rb_ensure(rb_yield, self, pgconn_finish, self);
        }
        return self;
}

Returns a string that is safe for inclusion in a SQL query as an identifier. Note: this is not a quote function for values, but for identifiers.

For example, in a typical SQL query: SELECT FOO FROM MYTABLE The identifier FOO is folded to lower case, so it actually means foo. If you really want to access the case-sensitive field name FOO, use this function like PGconn.quote_ident(‘FOO’), which will return "FOO" (with double-quotes). PostgreSQL will see the double-quotes, and it will not fold to lower case.

Similarly, this function also protects against special characters, and other things that might allow SQL injection if the identifier comes from an untrusted source.

[Source]

/*
 * call-seq:
 *    PGconn.quote_ident( str ) -> String
 *    conn.quote_ident( str ) -> String
 *
 * Returns a string that is safe for inclusion in a SQL query as an
 * identifier. Note: this is not a quote function for values, but for
 * identifiers.
 * 
 * For example, in a typical SQL query: <tt>SELECT FOO FROM MYTABLE</tt>
 * The identifier <tt>FOO</tt> is folded to lower case, so it actually
 * means <tt>foo</tt>. If you really want to access the case-sensitive
 * field name <tt>FOO</tt>, use this function like
 * <tt>PGconn.quote_ident('FOO')</tt>, which will return <tt>"FOO"</tt>
 * (with double-quotes). PostgreSQL will see the double-quotes, and
 * it will not fold to lower case.
 * 
 * Similarly, this function also protects against special characters,
 * and other things that might allow SQL injection if the identifier
 * comes from an untrusted source.
 */
static VALUE
pgconn_s_quote_ident(VALUE self, VALUE in_str)
{
        VALUE ret;
        char *str = StringValuePtr(in_str);
        /* result size at most NAMEDATALEN*2 plus surrounding
         * double-quotes. */
        char buffer[NAMEDATALEN*2+2];
        unsigned int i=0,j=0;

        if(strlen(str) >= NAMEDATALEN) {
                rb_raise(rb_eArgError, 
                        "Input string is longer than NAMEDATALEN-1 (%d)",
                        NAMEDATALEN-1);
        }
        buffer[j++] = '"';
        for(i = 0; i < strlen(str) && str[i]; i++) {
                if(str[i] == '"') 
                        buffer[j++] = '"';
                buffer[j++] = str[i];
        }
        buffer[j++] = '"';
        ret = rb_str_new(buffer,j);
        OBJ_INFECT(ret, in_str);
        return ret;
}

Converts an escaped string representation of binary data into binary data — the reverse of escape_bytea. This is needed when retrieving bytea data in text format, but not when retrieving it in binary format.

[Source]

/*
 * call-seq:
 *   PGconn.unescape_bytea( string )
 *
 * Converts an escaped string representation of binary data into binary data --- the
 * reverse of #escape_bytea. This is needed when retrieving +bytea+ data in text format,
 * but not when retrieving it in binary format.
 *
 */
static VALUE
pgconn_s_unescape_bytea(VALUE self, VALUE str)
{
        unsigned char *from, *to;
        size_t to_len;
        VALUE ret;

        Check_Type(str, T_STRING);
        from = (unsigned char*)StringValuePtr(str);

        to = PQunescapeBytea(from, &to_len);

        ret = rb_str_new((char*)to, to_len);
        OBJ_INFECT(ret, str);
        PQfreemem(to);
        return ret;
}

Public Instance methods

This function has the same behavior as +PGconn#exec+, except that it‘s implemented using asynchronous command processing and ruby‘s rb_thread_select in order to allow other threads to process while waiting for the server to complete the request.

[Source]

/*
 * call-seq:
 *    conn.async_exec(sql [, params, result_format ] ) -> PGresult
 *    conn.async_exec(sql [, params, result_format ] ) {|pg_result| block }
 *
 * This function has the same behavior as +PGconn#exec+,
 * except that it's implemented using asynchronous command 
 * processing and ruby's +rb_thread_select+ in order to 
 * allow other threads to process while waiting for the
 * server to complete the request.
 */
static VALUE
pgconn_async_exec(int argc, VALUE *argv, VALUE self)
{
        VALUE rb_pgresult = Qnil;

        /* remove any remaining results from the queue */
        pgconn_block( 0, NULL, self ); /* wait for input (without blocking) before reading the last result */
        pgconn_get_last_result( self );

        pgconn_send_query( argc, argv, self );
        pgconn_block( 0, NULL, self );
        rb_pgresult = pgconn_get_last_result( self );

        if ( rb_block_given_p() ) {
                return rb_ensure( rb_yield, rb_pgresult, pgresult_clear, rb_pgresult );
        }
        return rb_pgresult;
}
async_query(...)

Alias for async_exec

Returns the process ID of the backend server process for this connection. Note that this is a PID on database server host.

[Source]

/*
 * call-seq:
 *    conn.backend_pid() -> Fixnum
 *
 * Returns the process ID of the backend server
 * process for this connection.
 * Note that this is a PID on database server host.
 */
static VALUE
pgconn_backend_pid(VALUE self)
{
        return INT2NUM(PQbackendPID(get_pgconn(self)));
}

Blocks until the server is no longer busy, or until the optional timeout is reached, whichever comes first. timeout is measured in seconds and can be fractional.

Returns false if timeout is reached, true otherwise.

If true is returned, +conn.is_busy+ will return false and +conn.get_result+ will not block.

[Source]

/*
 * call-seq:
 *    conn.block( [ timeout ] ) -> Boolean
 *
 * Blocks until the server is no longer busy, or until the 
 * optional _timeout_ is reached, whichever comes first.
 * _timeout_ is measured in seconds and can be fractional.
 * 
 * Returns +false+ if _timeout_ is reached, +true+ otherwise.
 * 
 * If +true+ is returned, +conn.is_busy+ will return +false+
 * and +conn.get_result+ will not block.
 */
static VALUE
pgconn_block( int argc, VALUE *argv, VALUE self ) {

Requests cancellation of the command currently being processed. (Only implemented in PostgreSQL >= 8.0)

Returns nil on success, or a string containing the error message if a failure occurs.

[Source]

/*
 * call-seq:
 *    conn.cancel() -> String
 *
 * Requests cancellation of the command currently being
 * processed. (Only implemented in PostgreSQL >= 8.0)
 *
 * Returns +nil+ on success, or a string containing the
 * error message if a failure occurs.
 */
static VALUE
pgconn_cancel(VALUE self)
{
#ifdef HAVE_PQGETCANCEL
        char errbuf[256];
        PGcancel *cancel;
        VALUE retval;
        int ret;

        cancel = PQgetCancel(get_pgconn(self));
        if(cancel == NULL)
                rb_raise(rb_ePGError,"Invalid connection!");

        ret = PQcancel(cancel, errbuf, 256);
        if(ret == 1)
                retval = Qnil;
        else
                retval = rb_str_new2(errbuf);

        PQfreeCancel(cancel);
        return retval;
#else
        rb_notimplement();
#endif
}
close()

Alias for finish

Returns an array of hashes. Each hash has the keys:

+:keyword+
the name of the option
+:envvar+
the environment variable to fall back to
+:compiled+
the compiled in option as a secondary fallback
+:val+
the option‘s current value, or nil if not known
+:label+
the label for the field
+:dispchar+
"" for normal, "D" for debug, and "*" for password
+:dispsize+
field size

[Source]

/*
 * call-seq:
 *    PGconn.conndefaults() -> Array
 *
 * Returns an array of hashes. Each hash has the keys:
 * [+:keyword+]
 *   the name of the option
 * [+:envvar+]
 *   the environment variable to fall back to
 * [+:compiled+]
 *   the compiled in option as a secondary fallback
 * [+:val+]
 *   the option's current value, or +nil+ if not known
 * [+:label+]
 *   the label for the field
 * [+:dispchar+]
 *   "" for normal, "D" for debug, and "*" for password
 * [+:dispsize+]
 *   field size
 */
static VALUE
pgconn_s_conndefaults(VALUE self)
{
        PQconninfoOption *options = PQconndefaults();
        VALUE ary = rb_ary_new();
        VALUE hash;
        int i = 0;

        for(i = 0; options[i].keyword != NULL; i++) {
                hash = rb_hash_new();
                if(options[i].keyword)
                        rb_hash_aset(hash, ID2SYM(rb_intern("keyword")), 
                                rb_str_new2(options[i].keyword));
                if(options[i].envvar)
                        rb_hash_aset(hash, ID2SYM(rb_intern("envvar")), 
                                rb_str_new2(options[i].envvar));
                if(options[i].compiled)
                        rb_hash_aset(hash, ID2SYM(rb_intern("compiled")), 
                                rb_str_new2(options[i].compiled));
                if(options[i].val)
                        rb_hash_aset(hash, ID2SYM(rb_intern("val")), 
                                rb_str_new2(options[i].val));
                if(options[i].label)
                        rb_hash_aset(hash, ID2SYM(rb_intern("label")), 
                                rb_str_new2(options[i].label));
                if(options[i].dispchar)
                        rb_hash_aset(hash, ID2SYM(rb_intern("dispchar")), 
                                rb_str_new2(options[i].dispchar));
                rb_hash_aset(hash, ID2SYM(rb_intern("dispsize")), 
                        INT2NUM(options[i].dispsize));
                rb_ary_push(ary, hash);
        }
        PQconninfoFree(options);
        return ary;
}

Returns one of:

PGRES_POLLING_READING
wait until the socket is ready to read
PGRES_POLLING_WRITING
wait until the socket is ready to write
PGRES_POLLING_FAILED
the asynchronous connection has failed
PGRES_POLLING_OK
the asynchronous connection is ready

Example:

  conn = PGconn.connect_start("dbname=mydatabase")
  socket = IO.for_fd(conn.socket)
  status = conn.connect_poll
  while(status != PGconn::PGRES_POLLING_OK) do
    # do some work while waiting for the connection to complete
    if(status == PGconn::PGRES_POLLING_READING)
      if(not select([socket], [], [], 10.0))
        raise "Asynchronous connection timed out!"
      end
    elsif(status == PGconn::PGRES_POLLING_WRITING)
      if(not select([], [socket], [], 10.0))
        raise "Asynchronous connection timed out!"
      end
    end
    status = conn.connect_poll
  end
  # now conn.status == CONNECTION_OK, and connection
  # is ready.

[Source]

/*
 * call-seq:
 *    conn.connect_poll() -> Fixnum
 *
 * Returns one of:
 * [+PGRES_POLLING_READING+]
 *   wait until the socket is ready to read
 * [+PGRES_POLLING_WRITING+]
 *   wait until the socket is ready to write
 * [+PGRES_POLLING_FAILED+]
 *   the asynchronous connection has failed
 * [+PGRES_POLLING_OK+]
 *   the asynchronous connection is ready
 *
 * Example:
 *   conn = PGconn.connect_start("dbname=mydatabase")
 *   socket = IO.for_fd(conn.socket)
 *   status = conn.connect_poll
 *   while(status != PGconn::PGRES_POLLING_OK) do
 *     # do some work while waiting for the connection to complete
 *     if(status == PGconn::PGRES_POLLING_READING)
 *       if(not select([socket], [], [], 10.0))
 *         raise "Asynchronous connection timed out!"
 *       end
 *     elsif(status == PGconn::PGRES_POLLING_WRITING)
 *       if(not select([], [socket], [], 10.0))
 *         raise "Asynchronous connection timed out!"
 *       end
 *     end
 *     status = conn.connect_poll
 *   end
 *   # now conn.status == CONNECTION_OK, and connection
 *   # is ready.
 */
static VALUE
pgconn_connect_poll(VALUE self)
{
        PostgresPollingStatusType status;
        status = PQconnectPoll(get_pgconn(self));
        return INT2FIX((int)status);
}

Returns true if the authentication method required a password, but none was available. false otherwise.

[Source]

/*
 * call-seq:
 *    conn.connection_needs_password() -> Boolean
 *
 * Returns +true+ if the authentication method required a
 * password, but none was available. +false+ otherwise.
 */
static VALUE
pgconn_connection_needs_password(VALUE self)
{
        return PQconnectionNeedsPassword(get_pgconn(self)) ? Qtrue : Qfalse;
}

Returns true if the authentication method used a caller-supplied password, false otherwise.

[Source]

/*
 * call-seq:
 *    conn.connection_used_password() -> Boolean
 *
 * Returns +true+ if the authentication method used
 * a caller-supplied password, +false+ otherwise.
 */
static VALUE
pgconn_connection_used_password(VALUE self)
{
        return PQconnectionUsedPassword(get_pgconn(self)) ? Qtrue : Qfalse;
}

If input is available from the server, consume it. After calling consume_input, you can check is_busy or notifies to see if the state has changed.

[Source]

/*
 * call-seq:
 *    conn.consume_input()
 *
 * If input is available from the server, consume it.
 * After calling +consume_input+, you can check +is_busy+
 * or *notifies* to see if the state has changed.
 */
static VALUE
pgconn_consume_input(self)
        VALUE self;
{
        VALUE error;
        PGconn *conn = get_pgconn(self);
        /* returns 0 on error */
        if(PQconsumeInput(conn) == 0) {
                error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn));
                rb_iv_set(error, "@connection", self);
                rb_exc_raise(error);
        }
        return Qnil;
}

Returns the connected database name.

[Source]

/*
 * call-seq:
 *    conn.db()
 *
 * Returns the connected database name.
 */
static VALUE
pgconn_db(VALUE self)
{
        char *db = PQdb(get_pgconn(self));
        if (!db) return Qnil;
        return rb_tainted_str_new2(db);
}

Retrieve information about the portal portal_name.

[Source]

/*
 * call-seq:
 *    conn.describe_portal( portal_name ) -> PGresult
 *
 * Retrieve information about the portal _portal_name_.
 */
static VALUE
pgconn_describe_portal(self, stmt_name)
        VALUE self, stmt_name;
{
        PGresult *result;
        VALUE rb_pgresult;
        PGconn *conn = get_pgconn(self);
        char *stmt;
        if(stmt_name == Qnil) {
                stmt = NULL;
        }
        else {
                Check_Type(stmt_name, T_STRING);
                stmt = StringValuePtr(stmt_name);
        }
        result = PQdescribePortal(conn, stmt);
        rb_pgresult = new_pgresult(result, conn);
        pgresult_check(self, rb_pgresult);
        return rb_pgresult;
}

Retrieve information about the prepared statement statement_name.

[Source]

/*
 * call-seq:
 *    conn.describe_prepared( statement_name ) -> PGresult
 *
 * Retrieve information about the prepared statement
 * _statement_name_.
 */
static VALUE
pgconn_describe_prepared(VALUE self, VALUE stmt_name)
{
        PGresult *result;
        VALUE rb_pgresult;
        PGconn *conn = get_pgconn(self);
        char *stmt;
        if(stmt_name == Qnil) {
                stmt = NULL;
        }
        else {
                Check_Type(stmt_name, T_STRING);
                stmt = StringValuePtr(stmt_name);
        }
        result = PQdescribePrepared(conn, stmt);
        rb_pgresult = new_pgresult(result, conn);
        pgresult_check(self, rb_pgresult);
        return rb_pgresult;
}

Returns the error message about connection.

[Source]

/*
 * call-seq:
 *    conn.error_message -> String
 *
 * Returns the error message about connection.
 */
static VALUE
pgconn_error_message(VALUE self)
{
        char *error = PQerrorMessage(get_pgconn(self));
        if (!error) return Qnil;
        return rb_tainted_str_new2(error);
}
escape(p1)

Alias for escape_string

Connection instance method for versions of 8.1 and higher of libpq uses PQescapeByteaConn, which is safer. Avoid calling as a class method, the class method uses the deprecated PQescapeBytea() API function.

Use the instance method version of this function, it is safer than the class method.

Escapes binary data for use within an SQL command with the type bytea.

Certain byte values must be escaped (but all byte values may be escaped) when used as part of a bytea literal in an SQL statement. In general, to escape a byte, it is converted into the three digit octal number equal to the octet value, and preceded by two backslashes. The single quote (’) and backslash (\) characters have special alternative escape sequences. escape_bytea performs this operation, escaping only the minimally required bytes.

Consider using exec_params, which avoids the need for passing values inside of SQL commands.

[Source]

/*
 * call-seq:
 *   conn.escape_bytea( string ) -> String 
 *
 * Connection instance method for versions of 8.1 and higher of libpq
 * uses PQescapeByteaConn, which is safer. Avoid calling as a class method,
 * the class method uses the deprecated PQescapeBytea() API function.
 *
 * Use the instance method version of this function, it is safer than the
 * class method.
 *
 * Escapes binary data for use within an SQL command with the type +bytea+.
 * 
 * Certain byte values must be escaped (but all byte values may be escaped)
 * when used as part of a +bytea+ literal in an SQL statement. In general, to
 * escape a byte, it is converted into the three digit octal number equal to
 * the octet value, and preceded by two backslashes. The single quote (') and
 * backslash (\) characters have special alternative escape sequences.
 * #escape_bytea performs this operation, escaping only the minimally required 
 * bytes.
 * 
 * Consider using exec_params, which avoids the need for passing values inside of 
 * SQL commands.
 */
static VALUE
pgconn_s_escape_bytea(VALUE self, VALUE str)
{
        unsigned char *from, *to;
        size_t from_len, to_len;
        VALUE ret;

        Check_Type(str, T_STRING);
        from      = (unsigned char*)RSTRING_PTR(str);
        from_len  = RSTRING_LEN(str);

        if(rb_obj_class(self) == rb_cPGconn) {
                to = PQescapeByteaConn(get_pgconn(self), from, from_len, &to_len);
        } else {
                to = PQescapeBytea( from, from_len, &to_len);
        }

        ret = rb_str_new((char*)to, to_len - 1);
        OBJ_INFECT(ret, str);
        PQfreemem(to);
        return ret;
}

Connection instance method for versions of 8.1 and higher of libpq uses PQescapeStringConn, which is safer. Avoid calling as a class method, the class method uses the deprecated PQescapeString() API function.

Returns a SQL-safe version of the String str. This is the preferred way to make strings safe for inclusion in SQL queries.

Consider using exec_params, which avoids the need for passing values inside of SQL commands.

Encoding of escaped string will be equal to client encoding of connection.

[Source]

/*
 * call-seq:
 *    conn.escape_string( str ) -> String
 *
 * Connection instance method for versions of 8.1 and higher of libpq
 * uses PQescapeStringConn, which is safer. Avoid calling as a class method,
 * the class method uses the deprecated PQescapeString() API function.
 * 
 * Returns a SQL-safe version of the String _str_.
 * This is the preferred way to make strings safe for inclusion in 
 * SQL queries.
 * 
 * Consider using exec_params, which avoids the need for passing values 
 * inside of SQL commands.
 *
 * Encoding of escaped string will be equal to client encoding of connection.
 */
static VALUE
pgconn_s_escape(VALUE self, VALUE string)
{
        char *escaped;
        int size,error;
        VALUE result;
#ifdef M17N_SUPPORTED   
        rb_encoding* enc;
#endif

        Check_Type(string, T_STRING);

        escaped = ALLOC_N(char, RSTRING_LEN(string) * 2 + 1);
        if(rb_obj_class(self) == rb_cPGconn) {
                size = PQescapeStringConn(get_pgconn(self), escaped, 
                        RSTRING_PTR(string), RSTRING_LEN(string), &error);
                if(error) {
                        xfree(escaped);
                        rb_raise(rb_ePGError, "%s", PQerrorMessage(get_pgconn(self)));
                }
        } else {
                size = PQescapeString(escaped, RSTRING_PTR(string),
                        RSTRING_LEN(string));
        }
        result = rb_str_new(escaped, size);
        xfree(escaped);
        OBJ_INFECT(result, string);

#ifdef M17N_SUPPORTED
        if(rb_obj_class(self) == rb_cPGconn) {
                enc = pgconn_get_client_encoding_as_rb_encoding(get_pgconn(self));
        } else {
                enc = rb_enc_get(string);
        }
        rb_enc_associate(result, enc);
#endif

        return result;
}

Sends SQL query request specified by sql to PostgreSQL. Returns a PGresult instance on success. On failure, it raises a PGError exception.

params is an optional array of the bind parameters for the SQL query. Each element of the params array may be either:

  a hash of the form:
    {:value  => String (value of bind parameter)
     :type   => Fixnum (oid of type of bind parameter)
     :format => Fixnum (0 for text, 1 for binary)
    }
  or, it may be a String. If it is a string, that is equivalent to the hash:
    { :value => <string value>, :type => 0, :format => 0 }

PostgreSQL bind parameters are represented as $1, $1, $2, etc., inside the SQL query. The 0th element of the params array is bound to $1, the 1st element is bound to $2, etc. nil is treated as NULL.

If the types are not specified, they will be inferred by PostgreSQL. Instead of specifying type oids, it‘s recommended to simply add explicit casts in the query to ensure that the right type is used.

For example: "SELECT $1::int"

The optional result_format should be 0 for text results, 1 for binary.

If the optional code block is given, it will be passed result as an argument, and the PGresult object will automatically be cleared when the block terminates. In this instance, conn.exec returns the value of the block.

[Source]

/*
 * call-seq:
 *    conn.exec(sql [, params, result_format ] ) -> PGresult
 *    conn.exec(sql [, params, result_format ] ) {|pg_result| block }
 *
 * Sends SQL query request specified by _sql_ to PostgreSQL.
 * Returns a PGresult instance on success.
 * On failure, it raises a PGError exception.
 *
 * +params+ is an optional array of the bind parameters for the SQL query.
 * Each element of the +params+ array may be either:
 *   a hash of the form:
 *     {:value  => String (value of bind parameter)
 *      :type   => Fixnum (oid of type of bind parameter)
 *      :format => Fixnum (0 for text, 1 for binary)
 *     }
 *   or, it may be a String. If it is a string, that is equivalent to the hash:
 *     { :value => <string value>, :type => 0, :format => 0 }
 * 
 * PostgreSQL bind parameters are represented as $1, $1, $2, etc.,
 * inside the SQL query. The 0th element of the +params+ array is bound
 * to $1, the 1st element is bound to $2, etc. +nil+ is treated as +NULL+.
 * 
 * If the types are not specified, they will be inferred by PostgreSQL.
 * Instead of specifying type oids, it's recommended to simply add
 * explicit casts in the query to ensure that the right type is used.
 *
 * For example: "SELECT $1::int"
 *
 * The optional +result_format+ should be 0 for text results, 1
 * for binary.
 *
 * If the optional code block is given, it will be passed <i>result</i> as an argument, 
 * and the PGresult object will  automatically be cleared when the block terminates. 
 * In this instance, <code>conn.exec</code> returns the value of the block.
 */
static VALUE
pgconn_exec(int argc, VALUE *argv, VALUE self)
{
        PGconn *conn = get_pgconn(self);
        PGresult *result = NULL;
        VALUE rb_pgresult;
        VALUE command, params, in_res_fmt;
        VALUE param, param_type, param_value, param_format;
        VALUE param_value_tmp;
        VALUE sym_type, sym_value, sym_format;
        VALUE gc_array;
        int i=0;
        int nParams;
        Oid *paramTypes;
        char ** paramValues;
        int *paramLengths;
        int *paramFormats;
        int resultFormat;

        rb_scan_args(argc, argv, "12", &command, &params, &in_res_fmt);

        Check_Type(command, T_STRING);

        /* If called with no parameters, use PQexec */
        if(NIL_P(params)) {
                result = PQexec(conn, StringValuePtr(command));
                rb_pgresult = new_pgresult(result, conn);
                pgresult_check(self, rb_pgresult);
                if (rb_block_given_p()) {
                        return rb_ensure(rb_yield, rb_pgresult, 
                                pgresult_clear, rb_pgresult);
                }
                return rb_pgresult;
        }

        /* If called with parameters, and optionally result_format,
         * use PQexecParams
         */
        Check_Type(params, T_ARRAY);

        if(NIL_P(in_res_fmt)) {
                resultFormat = 0;
        }
        else {
                resultFormat = NUM2INT(in_res_fmt);
        }

        gc_array = rb_ary_new();
        rb_gc_register_address(&gc_array);
        sym_type = ID2SYM(rb_intern("type"));
        sym_value = ID2SYM(rb_intern("value"));
        sym_format = ID2SYM(rb_intern("format"));
        nParams = RARRAY_LEN(params);
        paramTypes = ALLOC_N(Oid, nParams); 
        paramValues = ALLOC_N(char *, nParams);
        paramLengths = ALLOC_N(int, nParams);
        paramFormats = ALLOC_N(int, nParams);
        for(i = 0; i < nParams; i++) {
                param = rb_ary_entry(params, i);
                if (TYPE(param) == T_HASH) {
                        param_type = rb_hash_aref(param, sym_type);
                        param_value_tmp = rb_hash_aref(param, sym_value);
                        if(param_value_tmp == Qnil)
                                param_value = param_value_tmp;
                        else
                                param_value = rb_obj_as_string(param_value_tmp);
                        param_format = rb_hash_aref(param, sym_format);
                }
                else {
                        param_type = Qnil;
                        if(param == Qnil)
                                param_value = param;
                        else
                                param_value = rb_obj_as_string(param);
                        param_format = Qnil;
                }

                if(param_type == Qnil)
                        paramTypes[i] = 0;
                else
                        paramTypes[i] = NUM2INT(param_type);

                if(param_value == Qnil) {
                        paramValues[i] = NULL;
                        paramLengths[i] = 0;
                }
                else {
                        Check_Type(param_value, T_STRING);
                        /* make sure param_value doesn't get freed by the GC */
                        rb_ary_push(gc_array, param_value);
                        paramValues[i] = StringValuePtr(param_value);
                        paramLengths[i] = RSTRING_LEN(param_value);
                }

                if(param_format == Qnil)
                        paramFormats[i] = 0;
                else
                        paramFormats[i] = NUM2INT(param_format);
        }

        result = PQexecParams(conn, StringValuePtr(command), nParams, paramTypes, 
                (const char * const *)paramValues, paramLengths, paramFormats, resultFormat);

        rb_gc_unregister_address(&gc_array);

        xfree(paramTypes);
        xfree(paramValues);
        xfree(paramLengths);
        xfree(paramFormats);

        rb_pgresult = new_pgresult(result, conn);
        pgresult_check(self, rb_pgresult);
        if (rb_block_given_p()) {
                return rb_ensure(rb_yield, rb_pgresult, 
                        pgresult_clear, rb_pgresult);
        }
        return rb_pgresult;
}

Execute prepared named statement specified by statement_name. Returns a PGresult instance on success. On failure, it raises a PGError exception.

params is an array of the optional bind parameters for the SQL query. Each element of the params array may be either:

  a hash of the form:
    {:value  => String (value of bind parameter)
     :format => Fixnum (0 for text, 1 for binary)
    }
  or, it may be a String. If it is a string, that is equivalent to the hash:
    { :value => <string value>, :format => 0 }

PostgreSQL bind parameters are represented as $1, $1, $2, etc., inside the SQL query. The 0th element of the params array is bound to $1, the 1st element is bound to $2, etc. nil is treated as NULL.

The optional result_format should be 0 for text results, 1 for binary.

If the optional code block is given, it will be passed result as an argument, and the PGresult object will automatically be cleared when the block terminates. In this instance, conn.exec_prepared returns the value of the block.

[Source]

/*
 * call-seq:
 *    conn.exec_prepared(statement_name [, params, result_format ] ) -> PGresult
 *    conn.exec_prepared(statement_name [, params, result_format ] ) {|pg_result| block }
 *
 * Execute prepared named statement specified by _statement_name_.
 * Returns a PGresult instance on success.
 * On failure, it raises a PGError exception.
 *
 * +params+ is an array of the optional bind parameters for the 
 * SQL query. Each element of the +params+ array may be either:
 *   a hash of the form:
 *     {:value  => String (value of bind parameter)
 *      :format => Fixnum (0 for text, 1 for binary)
 *     }
 *   or, it may be a String. If it is a string, that is equivalent to the hash:
 *     { :value => <string value>, :format => 0 }
 * 
 * PostgreSQL bind parameters are represented as $1, $1, $2, etc.,
 * inside the SQL query. The 0th element of the +params+ array is bound
 * to $1, the 1st element is bound to $2, etc. +nil+ is treated as +NULL+.
 *
 * The optional +result_format+ should be 0 for text results, 1
 * for binary.
 *
 * If the optional code block is given, it will be passed <i>result</i> as an argument, 
 * and the PGresult object will  automatically be cleared when the block terminates. 
 * In this instance, <code>conn.exec_prepared</code> returns the value of the block.
 */
static VALUE
pgconn_exec_prepared(int argc, VALUE *argv, VALUE self)
{
        PGconn *conn = get_pgconn(self);
        PGresult *result = NULL;
        VALUE rb_pgresult;
        VALUE name, params, in_res_fmt;
        VALUE param, param_value, param_format;
        VALUE param_value_tmp;
        VALUE sym_value, sym_format;
        VALUE gc_array;
        int i = 0;
        int nParams;
        char ** paramValues;
        int *paramLengths;
        int *paramFormats;
        int resultFormat;


        rb_scan_args(argc, argv, "12", &name, &params, &in_res_fmt);
        Check_Type(name, T_STRING);

        if(NIL_P(params)) {
                params = rb_ary_new2(0);
                resultFormat = 0;
        }
        else {
                Check_Type(params, T_ARRAY);
        }

        if(NIL_P(in_res_fmt)) {
                resultFormat = 0;
        }
        else {
                resultFormat = NUM2INT(in_res_fmt);
        }

        gc_array = rb_ary_new();
        rb_gc_register_address(&gc_array);
        sym_value = ID2SYM(rb_intern("value"));
        sym_format = ID2SYM(rb_intern("format"));
        nParams = RARRAY_LEN(params);
        paramValues = ALLOC_N(char *, nParams);
        paramLengths = ALLOC_N(int, nParams);
        paramFormats = ALLOC_N(int, nParams);
        for(i = 0; i < nParams; i++) {
                param = rb_ary_entry(params, i);
                if (TYPE(param) == T_HASH) {
                        param_value_tmp = rb_hash_aref(param, sym_value);
                        if(param_value_tmp == Qnil)
                                param_value = param_value_tmp;
                        else
                                param_value = rb_obj_as_string(param_value_tmp);
                        param_format = rb_hash_aref(param, sym_format);
                }
                else {
                        if(param == Qnil)
                                param_value = param;
                        else
                                param_value = rb_obj_as_string(param);
                        param_format = INT2NUM(0);
                }
                if(param_value == Qnil) {
                        paramValues[i] = NULL;
                        paramLengths[i] = 0;
                }
                else {
                        Check_Type(param_value, T_STRING);
                        /* make sure param_value doesn't get freed by the GC */
                        rb_ary_push(gc_array, param_value);
                        paramValues[i] = StringValuePtr(param_value);
                        paramLengths[i] = RSTRING_LEN(param_value);
                }

                if(param_format == Qnil)
                        paramFormats[i] = 0;
                else
                        paramFormats[i] = NUM2INT(param_format);
        }

        result = PQexecPrepared(conn, StringValuePtr(name), nParams, 
                (const char * const *)paramValues, paramLengths, paramFormats, 
                resultFormat);

        rb_gc_unregister_address(&gc_array);

        xfree(paramValues);
        xfree(paramLengths);
        xfree(paramFormats);

        rb_pgresult = new_pgresult(result, conn);
        pgresult_check(self, rb_pgresult);
        if (rb_block_given_p()) {
                return rb_ensure(rb_yield, rb_pgresult, 
                        pgresult_clear, rb_pgresult);
        }
        return rb_pgresult;
}

defined in Ruby 1.9 or later.

  • Returns the server_encoding of the connected database as a Ruby Encoding object.
  • Maps ‘SQL_ASCII’ to ASCII-8BIT.

[Source]

/*
 * call-seq:
 *   conn.external_encoding() -> Encoding
 *
 * defined in Ruby 1.9 or later.
 * * Returns the server_encoding of the connected database as a Ruby Encoding object.
 * * Maps 'SQL_ASCII' to ASCII-8BIT.
 */
static VALUE
pgconn_external_encoding(VALUE self)
{
        VALUE enc;
        enc = rb_iv_get(self, "@external_encoding");
        if (RTEST(enc)) {
                return enc;
        }
        else {
                int i;
                VALUE query = rb_usascii_str_new_cstr("SHOW server_encoding");
                VALUE pgresult = pgconn_exec(1, &query, self);
                VALUE enc_name = rb_ensure(enc_server_encoding_getvalue, pgresult, pgresult_clear, pgresult);

                if (strcmp("SQL_ASCII", StringValuePtr(enc_name)) == 0) {
                        enc = rb_enc_from_encoding(rb_ascii8bit_encoding());
                        goto cache;
                }
                for (i = 0; i < sizeof(enc_pg2ruby_mapping)/sizeof(enc_pg2ruby_mapping[0]); ++i) {
                        if (strcmp(StringValuePtr(enc_name), enc_pg2ruby_mapping[i][0]) == 0) {
                                enc = rb_enc_from_encoding(rb_enc_find(enc_pg2ruby_mapping[i][1]));
                                goto cache;
                        }
                }

                /* Ruby 1.9.1 does not supoort JOHAB */
                if (strcmp(StringValuePtr(enc_name), "JOHAB") == 0) {
                        enc = rb_enc_from_encoding(find_or_create_johab());
                        goto cache;
                }

                /* fallback */
                enc = rb_enc_from_encoding(rb_enc_find(StringValuePtr(enc_name)));
        }

cache:
        rb_iv_set(self, "@external_encoding", enc);
        return enc;
}

Closes the backend connection.

[Source]

/*
 * call-seq:
 *    conn.finish()
 *
 * Closes the backend connection.
 */
static VALUE
pgconn_finish(VALUE self)
{
        PQfinish(get_pgconn(self));
        DATA_PTR(self) = NULL;
        return Qnil;
}

Attempts to flush any queued output data to the server. Returns true if data is successfully flushed, false if not (can only return false if connection is nonblocking. Raises PGError exception if some other failure occurred.

[Source]

/*
 * call-seq:
 *    conn.flush() -> Boolean
 *
 * Attempts to flush any queued output data to the server.
 * Returns +true+ if data is successfully flushed, +false+
 * if not (can only return +false+ if connection is
 * nonblocking.
 * Raises PGError exception if some other failure occurred.
 */
static VALUE
pgconn_flush(self)
        VALUE self;
{
        PGconn *conn = get_pgconn(self);
        int ret;
        VALUE error;
        ret = PQflush(conn);
        if(ret == -1) {
                error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn));
                rb_iv_set(error, "@connection", self);
                rb_exc_raise(error);
        }
        return (ret) ? Qfalse : Qtrue;
}

Returns the client encoding as a String.

[Source]

/*
 * call-seq:
 *    conn.get_client_encoding() -> String
 * 
 * Returns the client encoding as a String.
 */
static VALUE
pgconn_get_client_encoding(VALUE self)
{
        char *encoding = (char *)pg_encoding_to_char(PQclientEncoding(get_pgconn(self)));
        return rb_tainted_str_new2(encoding);
}

Return a string containing one row of data, nil if the copy is done, or false if the call would block (only possible if async is true).

[Source]

/*
 * call-seq:
 *    conn.get_copy_data( [ async = false ] ) -> String
 *
 * Return a string containing one row of data, +nil+
 * if the copy is done, or +false+ if the call would 
 * block (only possible if _async_ is true).
 *
 */
static VALUE
pgconn_get_copy_data(int argc, VALUE *argv, VALUE self )
{
        VALUE async_in;
        VALUE error;
        VALUE result_str;
        int ret;
        int async;
        char *buffer;
        PGconn *conn = get_pgconn(self);

        if (rb_scan_args(argc, argv, "01", &async_in) == 0)
                async = 0;
        else
                async = (async_in == Qfalse || async_in == Qnil) ? 0 : 1;

        ret = PQgetCopyData(conn, &buffer, async);
        if(ret == -2) { // error
                error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn));
                rb_iv_set(error, "@connection", self);
                rb_exc_raise(error);
        }
        if(ret == -1) { // No data left
                return Qnil;
        }
        if(ret == 0) { // would block
                return Qfalse;
        }
        result_str = rb_tainted_str_new(buffer, ret);
        PQfreemem(buffer);
        return result_str;
}

This function retrieves all available results on the current connection (from previously issued asynchronous commands like +send_query()+) and returns the last non-NULL result, or nil if no results are available.

This function is similar to +PGconn#get_result+ except that it is designed to get one and only one result.

[Source]

/*
 * call-seq:
 *    conn.get_last_result( ) -> PGresult
 *
 * This function retrieves all available results
 * on the current connection (from previously issued
 * asynchronous commands like +send_query()+) and
 * returns the last non-NULL result, or +nil+ if no
 * results are available.
 *
 * This function is similar to +PGconn#get_result+
 * except that it is designed to get one and only
 * one result.
 */
static VALUE
pgconn_get_last_result(VALUE self)
{
        PGconn *conn = get_pgconn(self);
        VALUE rb_pgresult = Qnil;
        PGresult *cur, *prev;


        cur = prev = NULL;
        while ((cur = PQgetResult(conn)) != NULL) {
                int status;

                if (prev) PQclear(prev);
                prev = cur;

                status = PQresultStatus(cur);
                if (status == PGRES_COPY_OUT || status == PGRES_COPY_IN)
                        break;
        }

        if (prev) {
                rb_pgresult = new_pgresult(prev, conn);
                pgresult_check(self, rb_pgresult);
        }

        return rb_pgresult;
}

Blocks waiting for the next result from a call to +PGconn#send_query+ (or another asynchronous command), and returns it. Returns nil if no more results are available.

Note: call this function repeatedly until it returns nil, or else you will not be able to issue further commands.

If the optional code block is given, it will be passed result as an argument, and the PGresult object will automatically be cleared when the block terminates. In this instance, conn.exec returns the value of the block.

[Source]

/*
 * call-seq:
 *    conn.get_result() -> PGresult
 *    conn.get_result() {|pg_result| block }
 *
 * Blocks waiting for the next result from a call to
 * +PGconn#send_query+ (or another asynchronous command), and returns
 * it. Returns +nil+ if no more results are available.
 *
 * Note: call this function repeatedly until it returns +nil+, or else
 * you will not be able to issue further commands.
 *
 * If the optional code block is given, it will be passed <i>result</i> as an argument, 
 * and the PGresult object will  automatically be cleared when the block terminates. 
 * In this instance, <code>conn.exec</code> returns the value of the block.
 */
static VALUE
pgconn_get_result(VALUE self)
{
        PGconn *conn = get_pgconn(self);
        PGresult *result;
        VALUE rb_pgresult;

        result = PQgetResult(conn);
        if(result == NULL)
                return Qnil;
        rb_pgresult = new_pgresult(result, conn);
        if (rb_block_given_p()) {
                return rb_ensure(rb_yield, rb_pgresult,
                        pgresult_clear, rb_pgresult);
        }
        return rb_pgresult;
}

Returns the connected server name.

[Source]

/*
 * call-seq:
 *    conn.host()
 *
 * Returns the connected server name.
 */
static VALUE
pgconn_host(VALUE self)
{
        char *host = PQhost(get_pgconn(self));
        if (!host) return Qnil;
        return rb_tainted_str_new2(host);
}

defined in Ruby 1.9 or later.

Returns:

  • an Encoding - client_encoding of the connection as a Ruby Encoding object.
  • nil - the client_encoding is ‘SQL_ASCII‘

[Source]

/*
 * call-seq:
 *   conn.internal_encoding() -> Encoding
 *
 * defined in Ruby 1.9 or later.
 *
 * Returns:
 * * an Encoding - client_encoding of the connection as a Ruby Encoding object.
 * * nil - the client_encoding is 'SQL_ASCII'
 */
static VALUE
pgconn_internal_encoding(VALUE self)
{
        return rb_enc_from_encoding(pgconn_get_client_encoding_as_rb_encoding(get_pgconn(self)));
}

A wrapper of +PGconn#set_client_encoding+. defined in Ruby 1.9 or later.

value can be one of:

  • an Encoding
  • a String - a name of Encoding
  • nil - sets ‘SQL_ASCII’ to the client_encoding.

[Source]

/*
 * call-seq:
 *   conn.internal_encoding = value
 *
 * A wrapper of +PGconn#set_client_encoding+.
 * defined in Ruby 1.9 or later.
 *
 * +value+ can be one of:
 * * an Encoding
 * * a String - a name of Encoding
 * * +nil+ - sets 'SQL_ASCII' to the client_encoding.
 */
static VALUE
pgconn_internal_encoding_set(VALUE self, VALUE enc)
{
        if (NIL_P(enc)) {
                pgconn_set_client_encoding(self, rb_usascii_str_new_cstr("SQL_ASCII"));
                return enc;
        }
        else if (TYPE(enc) == T_STRING && strcasecmp("JOHAB", RSTRING_PTR(enc)) == 0) {
                pgconn_set_client_encoding(self, rb_usascii_str_new_cstr("JOHAB"));
                return enc;
        }
        else {
                int i;
                const char *name; 
                name = rb_enc_name(rb_to_encoding(enc));

                /* sequential search becuase rarely called */
                for (i = 0; i < sizeof(enc_pg2ruby_mapping)/sizeof(enc_pg2ruby_mapping[0]); ++i) {
                        if (strcmp(name, enc_pg2ruby_mapping[i][1]) == 0) {
                                if (PQsetClientEncoding(get_pgconn(self), enc_pg2ruby_mapping[i][0]) == -1) {
                                        VALUE server_encoding = pgconn_external_encoding(self);
                                        rb_raise(rb_eEncCompatError, "imcompatible character encodings: %s and %s",
                                                        rb_enc_name(rb_to_encoding(server_encoding)),
                                                        enc_pg2ruby_mapping[i][0]);
                                }
                                return enc;
                        }
                }

                /* Ruby 1.9.1 does not support JOHAB */
                if (strcasecmp(name, "JOHAB") == 0) {
                        pgconn_set_client_encoding(self, rb_usascii_str_new_cstr("JOHAB"));
                        return enc;
                }
        }

        enc = rb_inspect(enc);
        rb_raise(rb_ePGError, "unknown encoding: %s", StringValuePtr(enc));
}

Returns true if a command is busy, that is, if PQgetResult would block. Otherwise returns false.

[Source]

/*
 * call-seq:
 *    conn.is_busy() -> Boolean
 *
 * Returns +true+ if a command is busy, that is, if
 * PQgetResult would block. Otherwise returns +false+.
 */
static VALUE
pgconn_is_busy(self)
        VALUE self;
{
        return PQisBusy(get_pgconn(self)) ? Qtrue : Qfalse;
}

Returns true if a command is busy, that is, if PQgetResult would block. Otherwise returns false.

[Source]

/*
 * call-seq:
 *    conn.isnonblocking() -> Boolean
 *
 * Returns +true+ if a command is busy, that is, if
 * PQgetResult would block. Otherwise returns +false+.
 */
static VALUE
pgconn_isnonblocking(self)
        VALUE self;
{
        return PQisnonblocking(get_pgconn(self)) ? Qtrue : Qfalse;
}

Closes the postgres large object of lo_desc.

[Source]

/*
 * call-seq:
 *    conn.lo_close( lo_desc ) -> nil
 *
 * Closes the postgres large object of _lo_desc_.
 */
static VALUE
pgconn_loclose(VALUE self, VALUE in_lo_desc)
{
        PGconn *conn = get_pgconn(self);
        int lo_desc = NUM2INT(in_lo_desc);

        if(lo_close(conn,lo_desc) < 0)
                rb_raise(rb_ePGError,"lo_close failed");

        return Qnil;
}

Creates a large object with mode mode. Returns a large object Oid. On failure, it raises PGError exception.

[Source]

/*
 * call-seq:
 *    conn.lo_creat( [mode] ) -> Fixnum
 *
 * Creates a large object with mode _mode_. Returns a large object Oid.
 * On failure, it raises PGError exception.
 */
static VALUE
pgconn_locreat(int argc, VALUE *argv, VALUE self)
{
        Oid lo_oid;
        int mode;
        VALUE nmode;
        PGconn *conn = get_pgconn(self);

        if (rb_scan_args(argc, argv, "01", &nmode) == 0)
                mode = INV_READ;
        else
                mode = NUM2INT(nmode);

        lo_oid = lo_creat(conn, mode);
        if (lo_oid == 0)
                rb_raise(rb_ePGError, "lo_creat failed");

        return INT2FIX(lo_oid);
}

Creates a large object with oid oid. Returns the large object Oid. On failure, it raises PGError exception.

[Source]

/*
 * call-seq:
 *    conn.lo_create( oid ) -> Fixnum
 *
 * Creates a large object with oid _oid_. Returns the large object Oid.
 * On failure, it raises PGError exception.
 */
static VALUE
pgconn_locreate(VALUE self, VALUE in_lo_oid)
{
        Oid ret, lo_oid;
        PGconn *conn = get_pgconn(self);
        lo_oid = NUM2INT(in_lo_oid);

        ret = lo_create(conn, in_lo_oid);
        if (ret == InvalidOid)
                rb_raise(rb_ePGError, "lo_create failed");

        return INT2FIX(ret);
}

Saves a large object of oid to a file.

[Source]

/*
 * call-seq:
 *    conn.lo_export( oid, file ) -> nil
 *
 * Saves a large object of _oid_ to a _file_.
 */
static VALUE
pgconn_loexport(VALUE self, VALUE lo_oid, VALUE filename)
{
        PGconn *conn = get_pgconn(self);
        int oid;
        Check_Type(filename, T_STRING);

        oid = NUM2INT(lo_oid);
        if (oid < 0) {
                rb_raise(rb_ePGError, "invalid large object oid %d",oid);
        }

        if (lo_export(conn, oid, StringValuePtr(filename)) < 0) {
                rb_raise(rb_ePGError, "%s", PQerrorMessage(conn));
        }
        return Qnil;
}

Import a file to a large object. Returns a large object Oid.

On failure, it raises a PGError exception.

[Source]

/*
 * call-seq:
 *    conn.lo_import(file) -> Fixnum
 *
 * Import a file to a large object. Returns a large object Oid.
 *
 * On failure, it raises a PGError exception.
 */
static VALUE
pgconn_loimport(VALUE self, VALUE filename)
{
        Oid lo_oid;

        PGconn *conn = get_pgconn(self);

        Check_Type(filename, T_STRING);

        lo_oid = lo_import(conn, StringValuePtr(filename));
        if (lo_oid == 0) {
                rb_raise(rb_ePGError, "%s", PQerrorMessage(conn));
        }
        return INT2FIX(lo_oid);
}

Move the large object pointer lo_desc to offset offset. Valid values for whence are SEEK_SET, SEEK_CUR, and SEEK_END. (Or 0, 1, or 2.)

[Source]

/*
 * call-seq:
 *    conn.lo_lseek( lo_desc, offset, whence ) -> Fixnum
 *
 * Move the large object pointer _lo_desc_ to offset _offset_.
 * Valid values for _whence_ are +SEEK_SET+, +SEEK_CUR+, and +SEEK_END+.
 * (Or 0, 1, or 2.)
 */
static VALUE
pgconn_lolseek(VALUE self, VALUE in_lo_desc, VALUE offset, VALUE whence)
{
        PGconn *conn = get_pgconn(self);
        int lo_desc = NUM2INT(in_lo_desc);
        int ret;

        if((ret = lo_lseek(conn, lo_desc, NUM2INT(offset), NUM2INT(whence))) < 0) {
                rb_raise(rb_ePGError, "lo_lseek failed");
        }

        return INT2FIX(ret);
}

Open a large object of oid. Returns a large object descriptor instance on success. The mode argument specifies the mode for the opened large object,which is either INV_READ, or INV_WRITE.

If mode is omitted, the default is INV_READ.

[Source]

/*
 * call-seq:
 *    conn.lo_open( oid, [mode] ) -> Fixnum
 *
 * Open a large object of _oid_. Returns a large object descriptor 
 * instance on success. The _mode_ argument specifies the mode for
 * the opened large object,which is either +INV_READ+, or +INV_WRITE+.
 *
 * If _mode_ is omitted, the default is +INV_READ+.
 */
static VALUE
pgconn_loopen(int argc, VALUE *argv, VALUE self)
{
        Oid lo_oid;
        int fd, mode;
        VALUE nmode, selfid;
        PGconn *conn = get_pgconn(self);

        rb_scan_args(argc, argv, "11", &selfid, &nmode);
        lo_oid = NUM2INT(selfid);
        if(NIL_P(nmode))
                mode = INV_READ;
        else
                mode = NUM2INT(nmode);

        if((fd = lo_open(conn, lo_oid, mode)) < 0) {
                rb_raise(rb_ePGError, "can't open large object: %s", PQerrorMessage(conn));
        }
        return INT2FIX(fd);
}

Attempts to read len bytes from large object lo_desc, returns resulting data.

[Source]

/*
 * call-seq:
 *    conn.lo_read( lo_desc, len ) -> String
 *
 * Attempts to read _len_ bytes from large object _lo_desc_,
 * returns resulting data.
 */
static VALUE
pgconn_loread(VALUE self, VALUE in_lo_desc, VALUE in_len)
{
        int ret;
  PGconn *conn = get_pgconn(self);
        int len = NUM2INT(in_len);
        int lo_desc = NUM2INT(in_lo_desc);
        VALUE str;
        char *buffer;

  buffer = ALLOC_N(char, len);
        if(buffer == NULL)
                rb_raise(rb_eNoMemError, "ALLOC failed!");

        if (len < 0){
                rb_raise(rb_ePGError,"nagative length %d given", len);
        }

        if((ret = lo_read(conn, lo_desc, buffer, len)) < 0)
                rb_raise(rb_ePGError, "lo_read failed");

        if(ret == 0) {
                xfree(buffer);
                return Qnil;
        }

        str = rb_tainted_str_new(buffer, ret);
        xfree(buffer);

        return str;
}
lo_seek(p1, p2, p3)

Alias for lo_lseek

Returns the current position of the large object lo_desc.

[Source]

/*
 * call-seq:
 *    conn.lo_tell( lo_desc ) -> Fixnum
 *
 * Returns the current position of the large object _lo_desc_.
 */
static VALUE
pgconn_lotell(VALUE self, VALUE in_lo_desc)
{
        int position;
        PGconn *conn = get_pgconn(self);
        int lo_desc = NUM2INT(in_lo_desc);

        if((position = lo_tell(conn, lo_desc)) < 0)
                rb_raise(rb_ePGError,"lo_tell failed");

        return INT2FIX(position);
}

Truncates the large object lo_desc to size len.

[Source]

/*
 * call-seq:
 *    conn.lo_truncate( lo_desc, len ) -> nil
 *
 * Truncates the large object _lo_desc_ to size _len_.
 */
static VALUE
pgconn_lotruncate(VALUE self, VALUE in_lo_desc, VALUE in_len)
{
        PGconn *conn = get_pgconn(self);
        int lo_desc = NUM2INT(in_lo_desc);
        size_t len = NUM2INT(in_len);

        if(lo_truncate(conn,lo_desc,len) < 0)
                rb_raise(rb_ePGError,"lo_truncate failed");

        return Qnil;
}

Unlinks (deletes) the postgres large object of oid.

[Source]

/*
 * call-seq:
 *    conn.lo_unlink( oid ) -> nil
 *
 * Unlinks (deletes) the postgres large object of _oid_.
 */
static VALUE
pgconn_lounlink(VALUE self, VALUE in_oid)
{
        PGconn *conn = get_pgconn(self);
        int oid = NUM2INT(in_oid);

        if (oid < 0)
                rb_raise(rb_ePGError, "invalid oid %d",oid);

        if(lo_unlink(conn,oid) < 0)
                rb_raise(rb_ePGError,"lo_unlink failed");

        return Qnil;
}

Writes the string buffer to the large object lo_desc. Returns the number of bytes written.

[Source]

/*
 * call-seq:
 *    conn.lo_write( lo_desc, buffer ) -> Fixnum
 *
 * Writes the string _buffer_ to the large object _lo_desc_.
 * Returns the number of bytes written.
 */
static VALUE
pgconn_lowrite(VALUE self, VALUE in_lo_desc, VALUE buffer)
{
        int n;
        PGconn *conn = get_pgconn(self);
        int fd = NUM2INT(in_lo_desc);

        Check_Type(buffer, T_STRING);

        if( RSTRING_LEN(buffer) < 0) {
                rb_raise(rb_ePGError, "write buffer zero string");
        }
        if((n = lo_write(conn, fd, StringValuePtr(buffer), 
                                RSTRING_LEN(buffer))) < 0) {
                rb_raise(rb_ePGError, "lo_write failed: %s", PQerrorMessage(conn));
        }

        return INT2FIX(n);
}
loclose(p1)

Alias for lo_close

locreat(...)

Alias for lo_creat

locreate(p1)

Alias for lo_create

loexport(p1, p2)

Alias for lo_export

loimport(p1)

Alias for lo_import

lolseek(p1, p2, p3)

Alias for lo_lseek

loopen(...)

Alias for lo_open

loread(p1, p2)

Alias for lo_read

loseek(p1, p2, p3)

Alias for lo_lseek

lotell(p1)

Alias for lo_tell

lotruncate(p1, p2)

Alias for lo_truncate

lounlink(p1)

Alias for lo_unlink

lowrite(p1, p2)

Alias for lo_write

Constructs and empty PGresult with status status. status may be one of:

  • PGRES_EMPTY_QUERY
  • PGRES_COMMAND_OK
  • PGRES_TUPLES_OK
  • PGRES_COPY_OUT
  • PGRES_COPY_IN
  • PGRES_BAD_RESPONSE
  • PGRES_NONFATAL_ERROR
  • PGRES_FATAL_ERROR

[Source]

/*
 * call-seq:
 *    conn.make_empty_pgresult( status ) -> PGresult
 *
 * Constructs and empty PGresult with status _status_.
 * _status_ may be one of:
 * * +PGRES_EMPTY_QUERY+
 * * +PGRES_COMMAND_OK+
 * * +PGRES_TUPLES_OK+
 * * +PGRES_COPY_OUT+
 * * +PGRES_COPY_IN+
 * * +PGRES_BAD_RESPONSE+
 * * +PGRES_NONFATAL_ERROR+
 * * +PGRES_FATAL_ERROR+
 */
static VALUE
pgconn_make_empty_pgresult(VALUE self, VALUE status)
{
        PGresult *result;
        VALUE rb_pgresult;
        PGconn *conn = get_pgconn(self);
        result = PQmakeEmptyPGresult(conn, NUM2INT(status));
        rb_pgresult = new_pgresult(result, conn);
        pgresult_check(self, rb_pgresult);
        return rb_pgresult;
}
nonblocking?()

Alias for isnonblocking

Returns a hash of the unprocessed notifications. If there is no unprocessed notifier, it returns nil.

[Source]

/*
 * call-seq:
 *    conn.notifies()
 *
 * Returns a hash of the unprocessed notifications.
 * If there is no unprocessed notifier, it returns +nil+.
 */
static VALUE
pgconn_notifies(VALUE self)
{
        PGconn* conn = get_pgconn(self);
        PGnotify *notification;
        VALUE hash;
        VALUE sym_relname, sym_be_pid, sym_extra;
        VALUE relname, be_pid, extra;

        sym_relname = ID2SYM(rb_intern("relname"));
        sym_be_pid = ID2SYM(rb_intern("be_pid"));
        sym_extra = ID2SYM(rb_intern("extra"));

        notification = PQnotifies(conn);
        if (notification == NULL) {
                return Qnil;
        }

        hash = rb_hash_new();
        relname = rb_tainted_str_new2(notification->relname);
        be_pid = INT2NUM(notification->be_pid);
        extra = rb_tainted_str_new2(PGNOTIFY_EXTRA(notification));

        rb_hash_aset(hash, sym_relname, relname);
        rb_hash_aset(hash, sym_be_pid, be_pid);
        rb_hash_aset(hash, sym_extra, extra);

        PQfreemem(notification);
        return hash;
}
notifies_wait(...)

Alias for wait_for_notify

Returns backend option string.

[Source]

/*
 * call-seq:
 *    conn.options()
 *
 * Returns backend option string.
 */
static VALUE
pgconn_options(VALUE self)
{
        char *options = PQoptions(get_pgconn(self));
        if (!options) return Qnil;
        return rb_tainted_str_new2(options);
}

Returns the setting of parameter param_name, where param_name is one of

  • server_version
  • server_encoding
  • client_encoding
  • is_superuser
  • session_authorization
  • DateStyle
  • TimeZone
  • integer_datetimes
  • standard_conforming_strings

Returns nil if the value of the parameter is not known.

[Source]

/*
 * call-seq:
 *    conn.parameter_status( param_name ) -> String
 *
 * Returns the setting of parameter _param_name_, where
 * _param_name_ is one of
 * * +server_version+
 * * +server_encoding+
 * * +client_encoding+ 
 * * +is_superuser+
 * * +session_authorization+
 * * +DateStyle+
 * * +TimeZone+
 * * +integer_datetimes+
 * * +standard_conforming_strings+
 * 
 * Returns nil if the value of the parameter is not known.
 */
static VALUE
pgconn_parameter_status(VALUE self, VALUE param_name)
{
        const char *ret = PQparameterStatus(get_pgconn(self), 
                        StringValuePtr(param_name));
        if(ret == NULL)
                return Qnil;
        else
                return rb_tainted_str_new2(ret);
}

Returns the authenticated user name.

[Source]

/*
 * call-seq:
 *    conn.pass()
 *
 * Returns the authenticated user name.
 */
static VALUE
pgconn_pass(VALUE self)
{
        char *user = PQpass(get_pgconn(self));
        if (!user) return Qnil;
        return rb_tainted_str_new2(user);
}

Returns the connected server port number.

[Source]

/*
 * call-seq:
 *    conn.port()
 *
 * Returns the connected server port number.
 */
static VALUE
pgconn_port(VALUE self)
{
        char* port = PQport(get_pgconn(self));
        return INT2NUM(atol(port));
}

Prepares statement sql with name name to be executed later. Returns a PGresult instance on success. On failure, it raises a PGError exception.

param_types is an optional parameter to specify the Oids of the types of the parameters.

If the types are not specified, they will be inferred by PostgreSQL. Instead of specifying type oids, it‘s recommended to simply add explicit casts in the query to ensure that the right type is used.

For example: "SELECT $1::int"

PostgreSQL bind parameters are represented as $1, $1, $2, etc., inside the SQL query.

[Source]

/*
 * call-seq:
 *    conn.prepare(stmt_name, sql [, param_types ] ) -> PGresult
 *
 * Prepares statement _sql_ with name _name_ to be executed later.
 * Returns a PGresult instance on success.
 * On failure, it raises a PGError exception.
 *
 * +param_types+ is an optional parameter to specify the Oids of the 
 * types of the parameters.
 *
 * If the types are not specified, they will be inferred by PostgreSQL.
 * Instead of specifying type oids, it's recommended to simply add
 * explicit casts in the query to ensure that the right type is used.
 *
 * For example: "SELECT $1::int"
 * 
 * PostgreSQL bind parameters are represented as $1, $1, $2, etc.,
 * inside the SQL query.
 */
static VALUE
pgconn_prepare(int argc, VALUE *argv, VALUE self)
{
        PGconn *conn = get_pgconn(self);
        PGresult *result = NULL;
        VALUE rb_pgresult;
        VALUE name, command, in_paramtypes;
        VALUE param;
        int i = 0;
        int nParams = 0;
        Oid *paramTypes = NULL;

        rb_scan_args(argc, argv, "21", &name, &command, &in_paramtypes);
        Check_Type(name, T_STRING);
        Check_Type(command, T_STRING);

        if(! NIL_P(in_paramtypes)) {
                Check_Type(in_paramtypes, T_ARRAY);
                nParams = RARRAY_LEN(in_paramtypes);
                paramTypes = ALLOC_N(Oid, nParams); 
                for(i = 0; i < nParams; i++) {
                        param = rb_ary_entry(in_paramtypes, i);
                        Check_Type(param, T_FIXNUM);
                        if(param == Qnil)
                                paramTypes[i] = 0;
                        else
                                paramTypes[i] = NUM2INT(param);
                }
        }
        result = PQprepare(conn, StringValuePtr(name), StringValuePtr(command),
                        nParams, paramTypes);

        xfree(paramTypes);

        rb_pgresult = new_pgresult(result, conn);
        pgresult_check(self, rb_pgresult);
        return rb_pgresult;
}

The 3.0 protocol will normally be used when communicating with PostgreSQL 7.4 or later servers; pre-7.4 servers support only protocol 2.0. (Protocol 1.0 is obsolete and not supported by libpq.)

[Source]

/*
 * call-seq:
 *   conn.protocol_version -> Integer
 *
 * The 3.0 protocol will normally be used when communicating with PostgreSQL 7.4 
 * or later servers; pre-7.4 servers support only protocol 2.0. (Protocol 1.0 is 
 * obsolete and not supported by libpq.)
 */
static VALUE
pgconn_protocol_version(VALUE self)
{
        return INT2NUM(PQprotocolVersion(get_pgconn(self)));
}

Transmits buffer as copy data to the server. Returns true if the data was sent, false if it was not sent (false is only possible if the connection is in nonblocking mode, and this command would block).

Raises an exception if an error occurs.

[Source]

/*
 * call-seq:
 *    conn.put_copy_data( buffer ) -> Boolean
 *
 * Transmits _buffer_ as copy data to the server.
 * Returns true if the data was sent, false if it was
 * not sent (false is only possible if the connection
 * is in nonblocking mode, and this command would block).
 *
 * Raises an exception if an error occurs.
 */
static VALUE
pgconn_put_copy_data(self, buffer)
        VALUE self, buffer;
{
        int ret;
        VALUE error;
        PGconn *conn = get_pgconn(self);
        Check_Type(buffer, T_STRING);

        ret = PQputCopyData(conn, RSTRING_PTR(buffer),
                        RSTRING_LEN(buffer));
        if(ret == -1) {
                error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn));
                rb_iv_set(error, "@connection", self);
                rb_exc_raise(error);
        }
        return (ret) ? Qtrue : Qfalse;
}

Sends end-of-data indication to the server.

error_message is an optional parameter, and if set, forces the COPY command to fail with the string error_message.

Returns true if the end-of-data was sent, false if it was not sent (false is only possible if the connection is in nonblocking mode, and this command would block).

[Source]

/*
 * call-seq:
 *    conn.put_copy_end( [ error_message ] ) -> Boolean
 *
 * Sends end-of-data indication to the server.
 *
 * _error_message_ is an optional parameter, and if set,
 * forces the COPY command to fail with the string
 * _error_message_.
 *
 * Returns true if the end-of-data was sent, false if it was
 * not sent (false is only possible if the connection
 * is in nonblocking mode, and this command would block).
 */ 
static VALUE
pgconn_put_copy_end(int argc, VALUE *argv, VALUE self)
{
        VALUE str;
        VALUE error;
        int ret;
        char *error_message = NULL;
        PGconn *conn = get_pgconn(self);

        if (rb_scan_args(argc, argv, "01", &str) == 0)
                error_message = NULL;
        else
                error_message = StringValuePtr(str);

        ret = PQputCopyEnd(conn, error_message);
        if(ret == -1) {
                error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn));
                rb_iv_set(error, "@connection", self);
                rb_exc_raise(error);
        }
        return (ret) ? Qtrue : Qfalse;
}
query(...)

Alias for exec

Returns a string that is safe for inclusion in a SQL query as an identifier. Note: this is not a quote function for values, but for identifiers.

For example, in a typical SQL query: SELECT FOO FROM MYTABLE The identifier FOO is folded to lower case, so it actually means foo. If you really want to access the case-sensitive field name FOO, use this function like PGconn.quote_ident(‘FOO’), which will return "FOO" (with double-quotes). PostgreSQL will see the double-quotes, and it will not fold to lower case.

Similarly, this function also protects against special characters, and other things that might allow SQL injection if the identifier comes from an untrusted source.

[Source]

/*
 * call-seq:
 *    PGconn.quote_ident( str ) -> String
 *    conn.quote_ident( str ) -> String
 *
 * Returns a string that is safe for inclusion in a SQL query as an
 * identifier. Note: this is not a quote function for values, but for
 * identifiers.
 * 
 * For example, in a typical SQL query: <tt>SELECT FOO FROM MYTABLE</tt>
 * The identifier <tt>FOO</tt> is folded to lower case, so it actually
 * means <tt>foo</tt>. If you really want to access the case-sensitive
 * field name <tt>FOO</tt>, use this function like
 * <tt>PGconn.quote_ident('FOO')</tt>, which will return <tt>"FOO"</tt>
 * (with double-quotes). PostgreSQL will see the double-quotes, and
 * it will not fold to lower case.
 * 
 * Similarly, this function also protects against special characters,
 * and other things that might allow SQL injection if the identifier
 * comes from an untrusted source.
 */
static VALUE
pgconn_s_quote_ident(VALUE self, VALUE in_str)
{
        VALUE ret;
        char *str = StringValuePtr(in_str);
        /* result size at most NAMEDATALEN*2 plus surrounding
         * double-quotes. */
        char buffer[NAMEDATALEN*2+2];
        unsigned int i=0,j=0;

        if(strlen(str) >= NAMEDATALEN) {
                rb_raise(rb_eArgError, 
                        "Input string is longer than NAMEDATALEN-1 (%d)",
                        NAMEDATALEN-1);
        }
        buffer[j++] = '"';
        for(i = 0; i < strlen(str) && str[i]; i++) {
                if(str[i] == '"') 
                        buffer[j++] = '"';
                buffer[j++] = str[i];
        }
        buffer[j++] = '"';
        ret = rb_str_new(buffer,j);
        OBJ_INFECT(ret, in_str);
        return ret;
}

Resets the backend connection. This method closes the backend connection and tries to re-connect.

[Source]

/*
 * call-seq:
 *    conn.reset()
 *
 * Resets the backend connection. This method closes the 
 * backend connection and tries to re-connect.
 */
static VALUE
pgconn_reset(VALUE self)
{
        PQreset(get_pgconn(self));
        return self;
}

Checks the status of a connection reset operation. See PGconn#connect_start and PGconn#connect_poll for usage information and return values.

[Source]

/*
 * call-seq:
 *    conn.reset_poll -> Fixnum
 *
 * Checks the status of a connection reset operation.
 * See PGconn#connect_start and PGconn#connect_poll for
 * usage information and return values.
 */
static VALUE
pgconn_reset_poll(VALUE self)
{
        PostgresPollingStatusType status;
        status = PQresetPoll(get_pgconn(self));
        return INT2FIX((int)status);
}

Initiate a connection reset in a nonblocking manner. This will close the current connection and attempt to reconnect using the same connection parameters. Use PGconn#reset_poll to check the status of the connection reset.

[Source]

/*
 * call-seq:
 *    conn.reset_start() -> nil
 *
 * Initiate a connection reset in a nonblocking manner.
 * This will close the current connection and attempt to
 * reconnect using the same connection parameters.
 * Use PGconn#reset_poll to check the status of the 
 * connection reset.
 */
static VALUE
pgconn_reset_start(VALUE self)
{
        if(PQresetStart(get_pgconn(self)) == 0)
                rb_raise(rb_ePGError, "reset has failed");
        return Qnil;
}

Asynchronously send command to the server. Does not block. Use in combination with +conn.get_result+.

[Source]

/*
 * call-seq:
 *    conn.send_describe_portal( portal_name ) -> nil
 *
 * Asynchronously send _command_ to the server. Does not block. 
 * Use in combination with +conn.get_result+.
 */
static VALUE
pgconn_send_describe_portal(VALUE self, VALUE portal)
{
        VALUE error;
        PGconn *conn = get_pgconn(self);
        /* returns 0 on failure */
        if(PQsendDescribePortal(conn,StringValuePtr(portal)) == 0) {
                error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn));
                rb_iv_set(error, "@connection", self);
                rb_exc_raise(error);
        }
        return Qnil;
}

Asynchronously send command to the server. Does not block. Use in combination with +conn.get_result+.

[Source]

/*
 * call-seq:
 *    conn.send_describe_prepared( statement_name ) -> nil
 *
 * Asynchronously send _command_ to the server. Does not block. 
 * Use in combination with +conn.get_result+.
 */
static VALUE
pgconn_send_describe_prepared(VALUE self, VALUE stmt_name)
{
        VALUE error;
        PGconn *conn = get_pgconn(self);
        /* returns 0 on failure */
        if(PQsendDescribePrepared(conn,StringValuePtr(stmt_name)) == 0) {
                error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn));
                rb_iv_set(error, "@connection", self);
                rb_exc_raise(error);
        }
        return Qnil;
}

Prepares statement sql with name name to be executed later. Sends prepare command asynchronously, and returns immediately. On failure, it raises a PGError exception.

param_types is an optional parameter to specify the Oids of the types of the parameters.

If the types are not specified, they will be inferred by PostgreSQL. Instead of specifying type oids, it‘s recommended to simply add explicit casts in the query to ensure that the right type is used.

For example: "SELECT $1::int"

PostgreSQL bind parameters are represented as $1, $1, $2, etc., inside the SQL query.

[Source]

/*
 * call-seq:
 *    conn.send_prepare( stmt_name, sql [, param_types ] ) -> nil
 *
 * Prepares statement _sql_ with name _name_ to be executed later.
 * Sends prepare command asynchronously, and returns immediately.
 * On failure, it raises a PGError exception.
 *
 * +param_types+ is an optional parameter to specify the Oids of the 
 * types of the parameters.
 *
 * If the types are not specified, they will be inferred by PostgreSQL.
 * Instead of specifying type oids, it's recommended to simply add
 * explicit casts in the query to ensure that the right type is used.
 *
 * For example: "SELECT $1::int"
 * 
 * PostgreSQL bind parameters are represented as $1, $1, $2, etc.,
 * inside the SQL query.
 */
static VALUE
pgconn_send_prepare(int argc, VALUE *argv, VALUE self)
{
        PGconn *conn = get_pgconn(self);
        int result;
        VALUE name, command, in_paramtypes;
        VALUE param;
        VALUE error;
        int i = 0;
        int nParams = 0;
        Oid *paramTypes = NULL;

        rb_scan_args(argc, argv, "21", &name, &command, &in_paramtypes);
        Check_Type(name, T_STRING);
        Check_Type(command, T_STRING);

        if(! NIL_P(in_paramtypes)) {
                Check_Type(in_paramtypes, T_ARRAY);
                nParams = RARRAY_LEN(in_paramtypes);
                paramTypes = ALLOC_N(Oid, nParams); 
                for(i = 0; i < nParams; i++) {
                        param = rb_ary_entry(in_paramtypes, i);
                        Check_Type(param, T_FIXNUM);
                        if(param == Qnil)
                                paramTypes[i] = 0;
                        else
                                paramTypes[i] = NUM2INT(param);
                }
        }
        result = PQsendPrepare(conn, StringValuePtr(name), StringValuePtr(command),
                        nParams, paramTypes);

        xfree(paramTypes);

        if(result == 0) {
                error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn));
                rb_iv_set(error, "@connection", self);
                rb_exc_raise(error);
        }
        return Qnil;
}

Sends SQL query request specified by sql to PostgreSQL for asynchronous processing, and immediately returns. On failure, it raises a PGError exception.

params is an optional array of the bind parameters for the SQL query. Each element of the params array may be either:

  a hash of the form:
    {:value  => String (value of bind parameter)
     :type   => Fixnum (oid of type of bind parameter)
     :format => Fixnum (0 for text, 1 for binary)
    }
  or, it may be a String. If it is a string, that is equivalent to the hash:
    { :value => <string value>, :type => 0, :format => 0 }

PostgreSQL bind parameters are represented as $1, $1, $2, etc., inside the SQL query. The 0th element of the params array is bound to $1, the 1st element is bound to $2, etc. nil is treated as NULL.

If the types are not specified, they will be inferred by PostgreSQL. Instead of specifying type oids, it‘s recommended to simply add explicit casts in the query to ensure that the right type is used.

For example: "SELECT $1::int"

The optional result_format should be 0 for text results, 1 for binary.

[Source]

/*
 * call-seq:
 *    conn.send_query(sql [, params, result_format ] ) -> nil
 *
 * Sends SQL query request specified by _sql_ to PostgreSQL for
 * asynchronous processing, and immediately returns.
 * On failure, it raises a PGError exception.
 *
 * +params+ is an optional array of the bind parameters for the SQL query.
 * Each element of the +params+ array may be either:
 *   a hash of the form:
 *     {:value  => String (value of bind parameter)
 *      :type   => Fixnum (oid of type of bind parameter)
 *      :format => Fixnum (0 for text, 1 for binary)
 *     }
 *   or, it may be a String. If it is a string, that is equivalent to the hash:
 *     { :value => <string value>, :type => 0, :format => 0 }
 * 
 * PostgreSQL bind parameters are represented as $1, $1, $2, etc.,
 * inside the SQL query. The 0th element of the +params+ array is bound
 * to $1, the 1st element is bound to $2, etc. +nil+ is treated as +NULL+.
 * 
 * If the types are not specified, they will be inferred by PostgreSQL.
 * Instead of specifying type oids, it's recommended to simply add
 * explicit casts in the query to ensure that the right type is used.
 *
 * For example: "SELECT $1::int"
 *
 * The optional +result_format+ should be 0 for text results, 1
 * for binary.
 */
static VALUE
pgconn_send_query(int argc, VALUE *argv, VALUE self)
{
        PGconn *conn = get_pgconn(self);
        int result;
        VALUE command, params, in_res_fmt;
        VALUE param, param_type, param_value, param_format;
        VALUE param_value_tmp;
        VALUE sym_type, sym_value, sym_format;
        VALUE gc_array;
        VALUE error;
        int i=0;
        int nParams;
        Oid *paramTypes;
        char ** paramValues;
        int *paramLengths;
        int *paramFormats;
        int resultFormat;

        rb_scan_args(argc, argv, "12", &command, &params, &in_res_fmt);
        Check_Type(command, T_STRING);

        /* If called with no parameters, use PQsendQuery */
        if(NIL_P(params)) {
                if(PQsendQuery(conn,StringValuePtr(command)) == 0) {
                        error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn));
                        rb_iv_set(error, "@connection", self);
                        rb_exc_raise(error);
                }
                return Qnil;
        }

        /* If called with parameters, and optionally result_format,
         * use PQsendQueryParams
         */
        Check_Type(params, T_ARRAY);

        if(NIL_P(in_res_fmt)) {
                resultFormat = 0;
        }
        else {
                resultFormat = NUM2INT(in_res_fmt);
        }

        gc_array = rb_ary_new();
        rb_gc_register_address(&gc_array);
        sym_type = ID2SYM(rb_intern("type"));
        sym_value = ID2SYM(rb_intern("value"));
        sym_format = ID2SYM(rb_intern("format"));
        nParams = RARRAY_LEN(params);
        paramTypes = ALLOC_N(Oid, nParams); 
        paramValues = ALLOC_N(char *, nParams);
        paramLengths = ALLOC_N(int, nParams);
        paramFormats = ALLOC_N(int, nParams);
        for(i = 0; i < nParams; i++) {
                param = rb_ary_entry(params, i);
                if (TYPE(param) == T_HASH) {
                        param_type = rb_hash_aref(param, sym_type);
                        param_value_tmp = rb_hash_aref(param, sym_value);
                        if(param_value_tmp == Qnil)
                                param_value = param_value_tmp;
                        else
                                param_value = rb_obj_as_string(param_value_tmp);
                        param_format = rb_hash_aref(param, sym_format);
                }
                else {
                        param_type = INT2NUM(0);
                        if(param == Qnil)
                                param_value = param;
                        else
                                param_value = rb_obj_as_string(param);
                        param_format = INT2NUM(0);
                }

                if(param_type == Qnil)
                        paramTypes[i] = 0;
                else
                        paramTypes[i] = NUM2INT(param_type);

                if(param_value == Qnil) {
                        paramValues[i] = NULL;
                        paramLengths[i] = 0;
                }
                else {
                        Check_Type(param_value, T_STRING);
                        /* make sure param_value doesn't get freed by the GC */
                        rb_ary_push(gc_array, param_value);
                        paramValues[i] = StringValuePtr(param_value);
                        paramLengths[i] = RSTRING_LEN(param_value);
                }

                if(param_format == Qnil)
                        paramFormats[i] = 0;
                else
                        paramFormats[i] = NUM2INT(param_format);
        }

        result = PQsendQueryParams(conn, StringValuePtr(command), nParams, paramTypes, 
                (const char * const *)paramValues, paramLengths, paramFormats, resultFormat);

        rb_gc_unregister_address(&gc_array);   

        xfree(paramTypes);
        xfree(paramValues);
        xfree(paramLengths);
        xfree(paramFormats);

        if(result == 0) {
                error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn));
                rb_iv_set(error, "@connection", self);
                rb_exc_raise(error);
        }
        return Qnil;
}

Execute prepared named statement specified by statement_name asynchronously, and returns immediately. On failure, it raises a PGError exception.

params is an array of the optional bind parameters for the SQL query. Each element of the params array may be either:

  a hash of the form:
    {:value  => String (value of bind parameter)
     :format => Fixnum (0 for text, 1 for binary)
    }
  or, it may be a String. If it is a string, that is equivalent to the hash:
    { :value => <string value>, :format => 0 }

PostgreSQL bind parameters are represented as $1, $1, $2, etc., inside the SQL query. The 0th element of the params array is bound to $1, the 1st element is bound to $2, etc. nil is treated as NULL.

The optional result_format should be 0 for text results, 1 for binary.

[Source]

/*
 * call-seq:
 *    conn.send_query_prepared( statement_name [, params, result_format ] )
 *      -> nil
 *
 * Execute prepared named statement specified by _statement_name_
 * asynchronously, and returns immediately.
 * On failure, it raises a PGError exception.
 *
 * +params+ is an array of the optional bind parameters for the 
 * SQL query. Each element of the +params+ array may be either:
 *   a hash of the form:
 *     {:value  => String (value of bind parameter)
 *      :format => Fixnum (0 for text, 1 for binary)
 *     }
 *   or, it may be a String. If it is a string, that is equivalent to the hash:
 *     { :value => <string value>, :format => 0 }
 * 
 * PostgreSQL bind parameters are represented as $1, $1, $2, etc.,
 * inside the SQL query. The 0th element of the +params+ array is bound
 * to $1, the 1st element is bound to $2, etc. +nil+ is treated as +NULL+.
 *
 * The optional +result_format+ should be 0 for text results, 1
 * for binary.
 */
static VALUE
pgconn_send_query_prepared(int argc, VALUE *argv, VALUE self)
{
        PGconn *conn = get_pgconn(self);
        int result;
        VALUE name, params, in_res_fmt;
        VALUE param, param_value, param_format;
        VALUE param_value_tmp;
        VALUE sym_value, sym_format;
        VALUE gc_array;
        VALUE error;
        int i = 0;
        int nParams;
        char ** paramValues;
        int *paramLengths;
        int *paramFormats;
        int resultFormat;

        rb_scan_args(argc, argv, "12", &name, &params, &in_res_fmt);
        Check_Type(name, T_STRING);

        if(NIL_P(params)) {
                params = rb_ary_new2(0);
                resultFormat = 0;
        }
        else {
                Check_Type(params, T_ARRAY);
        }

        if(NIL_P(in_res_fmt)) {
                resultFormat = 0;
        }
        else {
                resultFormat = NUM2INT(in_res_fmt);
        }

        gc_array = rb_ary_new();
        rb_gc_register_address(&gc_array);
        sym_value = ID2SYM(rb_intern("value"));
        sym_format = ID2SYM(rb_intern("format"));
        nParams = RARRAY_LEN(params);
        paramValues = ALLOC_N(char *, nParams);
        paramLengths = ALLOC_N(int, nParams);
        paramFormats = ALLOC_N(int, nParams);
        for(i = 0; i < nParams; i++) {
                param = rb_ary_entry(params, i);
                if (TYPE(param) == T_HASH) {
                        param_value_tmp = rb_hash_aref(param, sym_value);
                        if(param_value_tmp == Qnil)
                                param_value = param_value_tmp;
                        else
                                param_value = rb_obj_as_string(param_value_tmp);
                        param_format = rb_hash_aref(param, sym_format);
                }
                else {
                        if(param == Qnil)
                                param_value = param;
                        else
                                param_value = rb_obj_as_string(param);
                        param_format = INT2NUM(0);
                }

                if(param_value == Qnil) {
                        paramValues[i] = NULL;
                        paramLengths[i] = 0;
                }
                else {
                        Check_Type(param_value, T_STRING);
                        /* make sure param_value doesn't get freed by the GC */
                        rb_ary_push(gc_array, param_value);
                        paramValues[i] = StringValuePtr(param_value);
                        paramLengths[i] = RSTRING_LEN(param_value);
                }

                if(param_format == Qnil)
                        paramFormats[i] = 0;
                else
                        paramFormats[i] = NUM2INT(param_format);
        }

        result = PQsendQueryPrepared(conn, StringValuePtr(name), nParams, 
                (const char * const *)paramValues, paramLengths, paramFormats, 
                resultFormat);

        rb_gc_unregister_address(&gc_array);

        xfree(paramValues);
        xfree(paramLengths);
        xfree(paramFormats);

        if(result == 0) {
                error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn));
                rb_iv_set(error, "@connection", self);
                rb_exc_raise(error);
        }
        return Qnil;
}

The number is formed by converting the major, minor, and revision numbers into two-decimal-digit numbers and appending them together. For example, version 7.4.2 will be returned as 70402, and version 8.1 will be returned as 80100 (leading zeroes are not shown). Zero is returned if the connection is bad.

[Source]

/* 
 * call-seq: 
 *   conn.server_version -> Integer
 * 
 * The number is formed by converting the major, minor, and revision
 * numbers into two-decimal-digit numbers and appending them together.
 * For example, version 7.4.2 will be returned as 70402, and version
 * 8.1 will be returned as 80100 (leading zeroes are not shown). Zero
 * is returned if the connection is bad.
 * 
 */
static VALUE
pgconn_server_version(VALUE self)
{
        return INT2NUM(PQserverVersion(get_pgconn(self)));
}

Sets the client encoding to the encoding String.

[Source]

/*
 * call-seq:
 *    conn.set_client_encoding( encoding )
 * 
 * Sets the client encoding to the _encoding_ String.
 */
static VALUE
pgconn_set_client_encoding(VALUE self, VALUE str)
{
        Check_Type(str, T_STRING);
        if ((PQsetClientEncoding(get_pgconn(self), StringValuePtr(str))) == -1){
                rb_raise(rb_ePGError, "invalid encoding name: %s",StringValuePtr(str));
        }
        return Qnil;
}

Sets connection‘s verbosity to verbosity and returns the previous setting. Available settings are:

  • PQERRORS_TERSE
  • PQERRORS_DEFAULT
  • PQERRORS_VERBOSE

[Source]

/*
 * call-seq:
 *    conn.set_error_verbosity( verbosity ) -> Fixnum
 *
 * Sets connection's verbosity to _verbosity_ and returns
 * the previous setting. Available settings are:
 * * PQERRORS_TERSE
 * * PQERRORS_DEFAULT
 * * PQERRORS_VERBOSE
 */
static VALUE
pgconn_set_error_verbosity(VALUE self, VALUE in_verbosity)
{
        PGconn *conn = get_pgconn(self);
        PGVerbosity verbosity = NUM2INT(in_verbosity);
        return INT2FIX(PQsetErrorVerbosity(conn, verbosity));
}

Notice and warning messages generated by the server are not returned by the query execution functions, since they do not imply failure of the query. Instead they are passed to a notice handling function, and execution continues normally after the handler returns. The default notice handling function prints the message on stderr, but the application can override this behavior by supplying its own handling function.

This function takes a new block to act as the handler, which should accept a single parameter that will be a PGresult object, and returns the Proc object previously set, or nil if it was previously the default.

If you pass no arguments, it will reset the handler to the default.

[Source]

/*
 * call-seq:
 *   conn.set_notice_processor {|message| ... } -> Proc
 *
 * Notice and warning messages generated by the server are not returned
 * by the query execution functions, since they do not imply failure of
 * the query. Instead they are passed to a notice handling function, and
 * execution continues normally after the handler returns. The default
 * notice handling function prints the message on <tt>stderr</tt>, but the
 * application can override this behavior by supplying its own handling
 * function.
 *
 * This function takes a new block to act as the handler, which should
 * accept a single parameter that will be a PGresult object, and returns 
 * the Proc object previously set, or +nil+ if it was previously the default.
 *
 * If you pass no arguments, it will reset the handler to the default.
 */
static VALUE
pgconn_set_notice_processor(VALUE self)
{
        VALUE proc, old_proc;
        PGconn *conn = get_pgconn(self);

        /* If default_notice_processor is unset, assume that the current 
         * notice processor is the default, and save it to a global variable. 
         * This should not be a problem because the default processor is
         * always the same, so won't vary among connections.
         */
        if(default_notice_processor == NULL)
                default_notice_processor = PQsetNoticeProcessor(conn, NULL, NULL);

        old_proc = rb_iv_get(self, "@notice_processor");
        if( rb_block_given_p() ) {
                proc = rb_block_proc();
                PQsetNoticeProcessor(conn, notice_processor_proxy, (void *)self);
        } else {
                /* if no block is given, set back to default */
                proc = Qnil;
                PQsetNoticeProcessor(conn, default_notice_processor, NULL);
        }

        rb_iv_set(self, "@notice_processor", proc);
        return old_proc;
}

Notice and warning messages generated by the server are not returned by the query execution functions, since they do not imply failure of the query. Instead they are passed to a notice handling function, and execution continues normally after the handler returns. The default notice handling function prints the message on stderr, but the application can override this behavior by supplying its own handling function.

This function takes a new block to act as the handler, which should accept a single parameter that will be a PGresult object, and returns the Proc object previously set, or nil if it was previously the default.

If you pass no arguments, it will reset the handler to the default.

[Source]

/*
 * call-seq:
 *   conn.set_notice_receiver {|result| ... } -> Proc
 *
 * Notice and warning messages generated by the server are not returned
 * by the query execution functions, since they do not imply failure of
 * the query. Instead they are passed to a notice handling function, and
 * execution continues normally after the handler returns. The default
 * notice handling function prints the message on <tt>stderr</tt>, but the
 * application can override this behavior by supplying its own handling
 * function.
 *
 * This function takes a new block to act as the handler, which should
 * accept a single parameter that will be a PGresult object, and returns 
 * the Proc object previously set, or +nil+ if it was previously the default.
 *
 * If you pass no arguments, it will reset the handler to the default.
 */
static VALUE
pgconn_set_notice_receiver(VALUE self)
{
        VALUE proc, old_proc;
        PGconn *conn = get_pgconn(self);

        /* If default_notice_receiver is unset, assume that the current 
         * notice receiver is the default, and save it to a global variable. 
         * This should not be a problem because the default receiver is
         * always the same, so won't vary among connections.
         */
        if(default_notice_receiver == NULL)
                default_notice_receiver = PQsetNoticeReceiver(conn, NULL, NULL);

        old_proc = rb_iv_get(self, "@notice_receiver");
        if( rb_block_given_p() ) {
                proc = rb_block_proc();
                PQsetNoticeReceiver(conn, notice_receiver_proxy, (void *)self);
        } else {
                /* if no block is given, set back to default */
                proc = Qnil;
                PQsetNoticeReceiver(conn, default_notice_receiver, NULL);
        }

        rb_iv_set(self, "@notice_receiver", proc);
        return old_proc;
}

Sets the nonblocking status of the connection. In the blocking state, calls to PGconn#send_query will block until the message is sent to the server, but will not wait for the query results. In the nonblocking state, calls to PGconn#send_query will return an error if the socket is not ready for writing. Note: This function does not affect PGconn#exec, because that function doesn‘t return until the server has processed the query and returned the results. Returns nil.

[Source]

/*
 * call-seq:
 *    conn.setnonblocking(Boolean) -> nil
 *
 * Sets the nonblocking status of the connection. 
 * In the blocking state, calls to PGconn#send_query
 * will block until the message is sent to the server,
 * but will not wait for the query results.
 * In the nonblocking state, calls to PGconn#send_query
 * will return an error if the socket is not ready for
 * writing.
 * Note: This function does not affect PGconn#exec, because
 * that function doesn't return until the server has 
 * processed the query and returned the results.
 * Returns +nil+.
 */
static VALUE
pgconn_setnonblocking(self, state)
        VALUE self, state;
{
        int arg;
        VALUE error;
        PGconn *conn = get_pgconn(self);
        if(state == Qtrue)
                arg = 1;
        else if (state == Qfalse)
                arg = 0;
        else
                rb_raise(rb_eArgError, "Boolean value expected");

        if(PQsetnonblocking(conn, arg) == -1) {
                error = rb_exc_new2(rb_ePGError, PQerrorMessage(conn));
                rb_iv_set(error, "@connection", self);
                rb_exc_raise(error);
        }
        return Qnil;
}

Returns the socket‘s file descriptor for this connection.

[Source]

/*
 * call-seq:
 *    conn.socket() -> Fixnum
 *
 * Returns the socket's file descriptor for this connection.
 */
static VALUE
pgconn_socket(VALUE self)
{
        int sd;
        if( (sd = PQsocket(get_pgconn(self))) < 0)
                rb_raise(rb_ePGError, "Can't get socket descriptor");
        return INT2NUM(sd);
}

Returns status of connection : CONNECTION_OK or CONNECTION_BAD

[Source]

/*
 * call-seq:
 *    conn.status()
 *
 * Returns status of connection : CONNECTION_OK or CONNECTION_BAD
 */
static VALUE
pgconn_status(VALUE self)
{
        return INT2NUM(PQstatus(get_pgconn(self)));
}

Enables tracing message passing between backend. The trace message will be written to the stream stream, which must implement a method fileno that returns a writable file descriptor.

[Source]

/*
 * call-seq:
 *    conn.trace( stream ) -> nil
 * 
 * Enables tracing message passing between backend. The 
 * trace message will be written to the stream _stream_,
 * which must implement a method +fileno+ that returns
 * a writable file descriptor.
 */
static VALUE
pgconn_trace(VALUE self, VALUE stream)
{
        VALUE fileno;
        FILE *new_fp;
        int old_fd, new_fd;
        VALUE new_file;

        if(rb_respond_to(stream,rb_intern("fileno")) == Qfalse)
                rb_raise(rb_eArgError, "stream does not respond to method: fileno");

        fileno = rb_funcall(stream, rb_intern("fileno"), 0);
        if(fileno == Qnil)
                rb_raise(rb_eArgError, "can't get file descriptor from stream");

        /* Duplicate the file descriptor and re-open
         * it. Then, make it into a ruby File object
         * and assign it to an instance variable.
         * This prevents a problem when the File
         * object passed to this function is closed
         * before the connection object is. */
        old_fd = NUM2INT(fileno);
        new_fd = dup(old_fd);
        new_fp = fdopen(new_fd, "w");

        if(new_fp == NULL)
                rb_raise(rb_eArgError, "stream is not writable");

        new_file = rb_funcall(rb_cIO, rb_intern("new"), 1, INT2NUM(new_fd));
        rb_iv_set(self, "@trace_stream", new_file);

        PQtrace(get_pgconn(self), new_fp);
        return Qnil;
}

Executes a BEGIN at the start of the block, and a COMMIT at the end of the block, or ROLLBACK if any exception occurs.

[Source]

/*
 * call-seq:
 *    conn.transaction { |conn| ... } -> nil
 *
 * Executes a +BEGIN+ at the start of the block,
 * and a +COMMIT+ at the end of the block, or 
 * +ROLLBACK+ if any exception occurs.
 */
static VALUE
pgconn_transaction(VALUE self)
{
        PGconn *conn = get_pgconn(self);
        PGresult *result;
        VALUE rb_pgresult;
        int status;

        if (rb_block_given_p()) {
                result = PQexec(conn, "BEGIN");
                rb_pgresult = new_pgresult(result, conn);
                pgresult_check(self, rb_pgresult);
                rb_protect(rb_yield, self, &status);
                if(status == 0) {
                        result = PQexec(conn, "COMMIT");
                        rb_pgresult = new_pgresult(result, conn);
                        pgresult_check(self, rb_pgresult);
                }
                else {
                        /* exception occurred, ROLLBACK and re-raise */
                        result = PQexec(conn, "ROLLBACK");
                        rb_pgresult = new_pgresult(result, conn);
                        pgresult_check(self, rb_pgresult);
                        rb_jump_tag(status);
                }

        }
        else {
                /* no block supplied? */
                rb_raise(rb_eArgError, "Must supply block for PGconn#transaction");
        }
        return Qnil;
}

returns one of the following statuses:

  PQTRANS_IDLE    = 0 (connection idle)
  PQTRANS_ACTIVE  = 1 (command in progress)
  PQTRANS_INTRANS = 2 (idle, within transaction block)
  PQTRANS_INERROR = 3 (idle, within failed transaction)
  PQTRANS_UNKNOWN = 4 (cannot determine status)

[Source]

/*
 * call-seq:
 *    conn.transaction_status()
 *
 * returns one of the following statuses:
 *   PQTRANS_IDLE    = 0 (connection idle)
 *   PQTRANS_ACTIVE  = 1 (command in progress)
 *   PQTRANS_INTRANS = 2 (idle, within transaction block)
 *   PQTRANS_INERROR = 3 (idle, within failed transaction)
 *   PQTRANS_UNKNOWN = 4 (cannot determine status)
 */
static VALUE
pgconn_transaction_status(VALUE self)
{
        return INT2NUM(PQtransactionStatus(get_pgconn(self)));
}

Returns the connected pgtty. (Obsolete)

[Source]

/*
 * call-seq:
 *    conn.tty()
 *
 * Returns the connected pgtty. (Obsolete)
 */
static VALUE
pgconn_tty(VALUE self)
{
        char *tty = PQtty(get_pgconn(self));
        if (!tty) return Qnil;
        return rb_tainted_str_new2(tty);
}

Converts an escaped string representation of binary data into binary data — the reverse of escape_bytea. This is needed when retrieving bytea data in text format, but not when retrieving it in binary format.

[Source]

/*
 * call-seq:
 *   PGconn.unescape_bytea( string )
 *
 * Converts an escaped string representation of binary data into binary data --- the
 * reverse of #escape_bytea. This is needed when retrieving +bytea+ data in text format,
 * but not when retrieving it in binary format.
 *
 */
static VALUE
pgconn_s_unescape_bytea(VALUE self, VALUE str)
{
        unsigned char *from, *to;
        size_t to_len;
        VALUE ret;

        Check_Type(str, T_STRING);
        from = (unsigned char*)StringValuePtr(str);

        to = PQunescapeBytea(from, &to_len);

        ret = rb_str_new((char*)to, to_len);
        OBJ_INFECT(ret, str);
        PQfreemem(to);
        return ret;
}

Disables the message tracing.

[Source]

/*
 * call-seq:
 *    conn.untrace() -> nil
 * 
 * Disables the message tracing.
 */
static VALUE
pgconn_untrace(VALUE self)
{
        VALUE trace_stream;
        PQuntrace(get_pgconn(self));
        trace_stream = rb_iv_get(self, "@trace_stream");
        rb_funcall(trace_stream, rb_intern("close"), 0);
        rb_iv_set(self, "@trace_stream", Qnil);
        return Qnil;
}

Returns the authenticated user name.

[Source]

/*
 * call-seq:
 *    conn.user()
 *
 * Returns the authenticated user name.
 */
static VALUE
pgconn_user(VALUE self)
{
        char *user = PQuser(get_pgconn(self));
        if (!user) return Qnil;
        return rb_tainted_str_new2(user);
}

Blocks while waiting for notification(s), or until the optional timeout is reached, whichever comes first. timeout is measured in seconds and can be fractional.

Returns nil if timeout is reached, the name of the NOTIFY event otherwise. If used in block form, passes the name of the NOTIFY event and the generating pid into the block.

Under PostgreSQL 9.0 and later, if the notification is sent with the optional payload string, it will be given to the block as the third argument.

[Source]

/*
 * call-seq:
 *    conn.wait_for_notify( [ timeout ] ) -> String
 *    conn.wait_for_notify( [ timeout ] ) { |event, pid| block }
 *    conn.wait_for_notify( [ timeout ] ) { |event, pid, payload| block } # PostgreSQL 9.0
 *
 * Blocks while waiting for notification(s), or until the optional
 * _timeout_ is reached, whichever comes first.  _timeout_ is
 * measured in seconds and can be fractional.
 *
 * Returns +nil+ if _timeout_ is reached, the name of the NOTIFY
 * event otherwise.  If used in block form, passes the name of the
 * NOTIFY +event+ and the generating +pid+ into the block.
 * 
 * Under PostgreSQL 9.0 and later, if the notification is sent with
 * the optional +payload+ string, it will be given to the block as the
 * third argument.
 * 
 */
static VALUE
pgconn_wait_for_notify(int argc, VALUE *argv, VALUE self)
{
        PGconn *conn = get_pgconn( self );
        PGnotify *notification;
        int sd = PQsocket( conn );
        int ret;
        struct timeval timeout;
        struct timeval *ptimeout = NULL;
        VALUE timeout_in = Qnil, relname = Qnil, be_pid = Qnil, extra = Qnil;
        double timeout_sec;
        fd_set sd_rset;
#ifdef _WIN32
        fd_set crt_sd_rset;
#endif

        if ( sd < 0 )
                rb_bug( "PQsocket(conn): couldn't fetch the connection's socket!" );

        rb_scan_args( argc, argv, "01", &timeout_in );

        if ( RTEST(timeout_in) ) {
                timeout_sec = NUM2DBL( timeout_in );
                timeout.tv_sec = (long)timeout_sec;
                timeout.tv_usec = (long)( (timeout_sec - (long)timeout_sec) * 1e6 );
                ptimeout = &timeout;
        }

        /* Check for notifications */
        while ( (notification = PQnotifies(conn)) == NULL ) {
                FD_ZERO( &sd_rset );
                FD_SET( sd, &sd_rset );

#ifdef _WIN32
                create_crt_fd(&sd_rset, &crt_sd_rset);
#endif

                /* Wait for the socket to become readable before checking again */
                ret = rb_thread_select( sd+1, &sd_rset, NULL, NULL, ptimeout );

#ifdef _WIN32
                cleanup_crt_fd(&sd_rset, &crt_sd_rset);
#endif

                if ( ret < 0 )
                        rb_sys_fail( 0 );

                /* Return nil if the select timed out */
                if ( ret == 0 ) return Qnil;

                /* Read the socket */
                if ( (ret = PQconsumeInput(conn)) != 1 )
                        rb_raise( rb_ePGError, "PQconsumeInput == %d: %s", ret, PQerrorMessage(conn) );
        }

        relname = rb_tainted_str_new2( notification->relname );
        ASSOCIATE_INDEX( relname, self );
        be_pid = INT2NUM( notification->be_pid );
#ifdef HAVE_ST_NOTIFY_EXTRA
        if ( *notification->extra ) {
                extra = rb_tainted_str_new2( notification->extra );
                ASSOCIATE_INDEX( extra, self );
        }
#endif
        PQfreemem( notification );

        if ( rb_block_given_p() )
                rb_yield_values( 3, relname, be_pid, extra );

        return relname;
}

[Validate]