# Oracle Functions (PDO_OCI)

## Installation

If the Oracle Database is on the same machine as PHP, the database software already contains the necessary libraries. When PHP is on a different machine, use the free » Oracle Instant Client libraries. For details refer to the OCI8 Requirements section.

Use --with-pdo-oci[=DIR] to install the PDO Oracle OCI extension, where the optional `[=DIR]` is the Oracle Home directory. `[=DIR]` defaults to the $ORACLE_HOME environment variable.

Use --with-pdo-oci=instantclient,prefix,version for an Oracle Instant Client SDK, where prefix and version are configured.

    // Using $ORACLE_HOME
    $ ./configure --with-pdo-oci

    // Using OIC for Linux with 10.2.0.3 RPMs with a /usr prefix
    $ ./configure --with-pdo-oci=instantclient,/usr,10.2.0.3

## Predefined Constants

The constants below are defined by this driver, and will only be available when the extension has been either compiled into PHP or dynamically loaded at runtime. In addition, these driver-specific constants should only be used if you are using this driver. Using driver-specific attributes with another driver may result in unexpected behaviour. PDO::getAttribute() may be used to obtain the `PDO::ATTR_DRIVER_NAME` attribute to check the driver, if your code can run against multiple drivers.

`PDO::OCI_ATTR_ACTION` (int)

  Provides a way to specify the action on the database session.

  This exists as of PHP 7.2.16 and 7.3.3

`PDO::OCI_ATTR_CLIENT_INFO` (int)

  Provides a way to specify the client info on the database session.

  This exists as of PHP 7.2.16 and 7.3.3

`PDO::OCI_ATTR_CLIENT_IDENTIFIER` (int)

  Provides a way to specify the client identifier on the database session.

  This exists as of PHP 7.2.16 and 7.3.3

`PDO::OCI_ATTR_MODULE` (int)

  Provides a way to specify the module on the database session.

  This exists as of PHP 7.2.16 and 7.3.3

## Table of Contents

- PDO_OCI DSN — Connecting to Oracle databases