require_wp_db()
- Since
- 2.5.0
- Source
wp-includes/load.php:677
$wpdb global.Compatibility
- WordPress
- since 2.5.0
- PHP
- 7.4–8.6-dev
- 6.7.7
- 6.8.8
- 6.9.7
- 7.0.4
- 7.1.0
Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.
Performance profile
How much work a call to require_wp_db() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.
- Cost class
- Heavy
- Scaling
- Constant
- Instructions
- 15–45
- Plugin surface
- None
- Called by
- 0
Reads or writes the filesystem via file_exists().
No loop in the body: the same number of instructions runs whatever you pass in.
Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 50.
Nothing here hands control to plugin code.
Nothing in core calls this; the cost is only what you spend yourself.
What it touches
- filesystemfilesystem access
file_exists()called directly
What one call costs · 1 distinct outcome
One number would be a lie: the work depends on which branch runs. These are every distinct cost require_wp_db() can have, taken from its control-flow graph on PHP 8.5.
| When | Instructions | Calls it makes |
|---|---|---|
| always | 15–45 | file_exists() |
Across PHP versions
| PHP | Compiled | Executed | Branches | Notes |
|---|---|---|---|---|
| 8.6-dev | 50 | 15–45 | 6 | |
| 8.5 | 50 | 15–45 | 6 | |
| 8.4 | 50 | 15–45 | 6 | |
| 8.3 | 50 | 15–45 | 6 | |
| 8.2 | 50 | 15–45 | 6 | |
| 8.1 | 50 | 15–45 | 6 | 4 fewer instructions than PHP 7.4 |
| 7.4 | 54 | 15–49 | 6 |
An instruction is not a fixed amount of time, so a matching count is not necessarily the same speed; what it rules out is a difference in the work itself.
Uses · 1
- wpdb::__construct()Connects to the database server and selects a database.
Source code
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 );}Changelog
Introduced in 2.5.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
About this page
- Parsed data
- Generated from the wordpress-develop 6.7.7 tag, from
src/wp-includes/load.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it. - Corrections
- Something wrong on this page? Report it and it gets fixed in the next regeneration.