# PostgreSQL Functions (PDO_PGSQL)

&reftitle.intro;

PDO_PGSQL is a driver that implements the PHP Data Objects (PDO) interface to enable access from PHP to PostgreSQL databases.

&reftitle.resources;

This extension defines a stream resource returned by `PDO::pgsqlLOBOpen`.

&reference.pdo-pgsql.configure;

PDO_PGSQL DSN

Connecting to PostgreSQL databases

&reftitle.description;

The PDO_PGSQL Data Source Name (DSN) is composed of the following elements, delimited by spaces or semicolons:

DSN prefix

- The DSN prefix is `pgsql:`.

`host`

- The hostname on which the database server resides.

`port`

- The port on which the database server is running.

`dbname`

- The name of the database.

`user`

- The name of the user for the connection. If you specify the user name in the DSN, PDO ignores the value of the user name argument in the PDO constructor.

`password`

- The password of the user for the connection. If you specify the password in the DSN, PDO ignores the value of the password argument in the PDO constructor.

The `bytea` fields are returned as streams.

&reftitle.examples;

#### PDO_PGSQL DSN examples

The following example shows a PDO_PGSQL DSN for connecting to a PostgreSQL database:

    pgsql:host=localhost;port=5432;dbname=testdb;user=bruce;password=mypass

&reference.pdo-pgsql.entities.PDO;