PHP 4, PHP 5, PHP 7, PHP 8
pg_connect - Open a PostgreSQL connection
Code Examples

pg_connect( string$connection_string, [int$flags = 0] ): PgSql\Connection|false

pg_connect opens a connection to a PostgreSQL database specified by the connection_string.

If a second call is made to pg_connect with the same connection_string as an existing connection, the existing connection will be returned unless you pass PGSQL_CONNECT_FORCE_NEW as flags.

The old syntax with multiple parameters $conn = pg_connect("host", "port", "options", "tty", "dbname") has been deprecated.



The connection_string can be empty to use all default parameters, or it can contain one or more parameter settings separated by whitespace. Each parameter setting is in the form keyword = value. Spaces around the equal sign are optional. To write an empty value or a value containing spaces, surround it with single quotes, e.g., keyword = 'a value'. Single quotes and backslashes within the value must be escaped with a backslash, i.e., \' and \\.

The currently recognized parameter keywords are: host, hostaddr, port, dbname (defaults to value of user), user, password, connect_timeout, options, tty (ignored), sslmode, requiressl (deprecated in favor of sslmode), and service. Which of these arguments exist depends on your PostgreSQL version.

The options parameter can be used to set command line parameters to be invoked by the server.


If PGSQL_CONNECT_FORCE_NEW is passed, then a new connection is created, even if the connection_string is identical to an existing connection.

If PGSQL_CONNECT_ASYNC is given, then the connection is established asynchronously. The state of the connection can then be checked via pg_connect_poll or pg_connection_status.

Return Values

Returns an PgSql\Connection instance on success, or false on failure.


Version Description
8.1.0 Returns an PgSql\Connection instance now; previously, a resource was returned.

Related Functions

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Function pg_connect:

PostgreSQL Functions

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