Title: require_wp_db
Published: April 25, 2014
Last modified: February 24, 2026

---

# require_wp_db()

## In this article

 * [Source](https://developer.wordpress.org/reference/functions/require_wp_db/?output_format=md#source)
 * [Related](https://developer.wordpress.org/reference/functions/require_wp_db/?output_format=md#related)
 * [Changelog](https://developer.wordpress.org/reference/functions/require_wp_db/?output_format=md#changelog)

[ Back to top](https://developer.wordpress.org/reference/functions/require_wp_db/?output_format=md#wp--skip-link--target)

Loads the database class file and instantiates the `$wpdb` global.

## 󠀁[Source](https://developer.wordpress.org/reference/functions/require_wp_db/?output_format=md#source)󠁿

    ```php
    function require_wp_db() {
    	global $wpdb;

    	require_once ABSPATH . WPINC . '/class-wpdb.php';

    	if ( file_exists( WP_CONTENT_DIR . '/db.php' ) ) {
    		require_once WP_CONTENT_DIR . '/db.php';
    	}

    	if ( isset( $wpdb ) ) {
    		return;
    	}

    	$dbuser     = defined( 'DB_USER' ) ? DB_USER : '';
    	$dbpassword = defined( 'DB_PASSWORD' ) ? DB_PASSWORD : '';
    	$dbname     = defined( 'DB_NAME' ) ? DB_NAME : '';
    	$dbhost     = defined( 'DB_HOST' ) ? DB_HOST : '';

    	$wpdb = new wpdb( $dbuser, $dbpassword, $dbname, $dbhost );
    }
    ```

[View all references](https://developer.wordpress.org/reference/files/wp-includes/load.php/)
[View on Trac](https://core.trac.wordpress.org/browser/tags/6.9.4/src/wp-includes/load.php#L706)
[View on GitHub](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/load.php#L706-L725)

## 󠀁[Related](https://developer.wordpress.org/reference/functions/require_wp_db/?output_format=md#related)󠁿

| Uses | Description | 
| [wpdb::__construct()](https://developer.wordpress.org/reference/classes/wpdb/__construct/)`wp-includes/class-wpdb.php` |

Connects to the database server and selects a database.

  |

## 󠀁[Changelog](https://developer.wordpress.org/reference/functions/require_wp_db/?output_format=md#changelog)󠁿

| Version | Description | 
| [2.5.0](https://developer.wordpress.org/reference/since/2.5.0/) | Introduced. |

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