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

---

# wpdb::has_cap( string $db_cap ): bool

## In this article

 * [Description](https://developer.wordpress.org/reference/classes/wpdb/has_cap/?output_format=md#description)
    - [See also](https://developer.wordpress.org/reference/classes/wpdb/has_cap/?output_format=md#see-also)
 * [Parameters](https://developer.wordpress.org/reference/classes/wpdb/has_cap/?output_format=md#parameters)
 * [Return](https://developer.wordpress.org/reference/classes/wpdb/has_cap/?output_format=md#return)
 * [Source](https://developer.wordpress.org/reference/classes/wpdb/has_cap/?output_format=md#source)
 * [Related](https://developer.wordpress.org/reference/classes/wpdb/has_cap/?output_format=md#related)
 * [Changelog](https://developer.wordpress.org/reference/classes/wpdb/has_cap/?output_format=md#changelog)

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

Determines whether the database or WPDB supports a particular feature.

## 󠀁[Description](https://developer.wordpress.org/reference/classes/wpdb/has_cap/?output_format=md#description)󠁿

Capability sniffs for the database server and current version of WPDB.

Database sniffs are based on the version of the database server in use.

WPDB sniffs are added as new features are introduced to allow theme and plugin developers
to determine feature support. This is to account for drop-ins which may introduce
feature support at a different time to WordPress.

### 󠀁[See also](https://developer.wordpress.org/reference/classes/wpdb/has_cap/?output_format=md#see-also)󠁿

 * [wpdb::db_version()](https://developer.wordpress.org/reference/classes/wpdb/db_version/)

## 󠀁[Parameters](https://developer.wordpress.org/reference/classes/wpdb/has_cap/?output_format=md#parameters)󠁿

 `$db_cap`stringrequired

The feature to check for. Accepts `'collation'`, `'group_concat'`, `'subqueries'`,`'
set_charset'`, `'utf8mb4'`, `'utf8mb4_520'`, or `'identifier_placeholders'`.

## 󠀁[Return](https://developer.wordpress.org/reference/classes/wpdb/has_cap/?output_format=md#return)󠁿

 bool True when the database feature is supported, false otherwise.

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

    ```php
    public function has_cap( $db_cap ) {
    	$db_version     = $this->db_version();
    	$db_server_info = $this->db_server_info();

    	/*
    	 * Account for MariaDB version being prefixed with '5.5.5-' on older PHP versions.
    	 *
    	 * Note: str_contains() is not used here, as this file can be included
    	 * directly outside of WordPress core, e.g. by HyperDB, in which case
    	 * the polyfills from wp-includes/compat.php are not loaded.
    	 */
    	if ( '5.5.5' === $db_version && false !== strpos( $db_server_info, 'MariaDB' )
    		&& PHP_VERSION_ID < 80016 // PHP 8.0.15 or older.
    	) {
    		// Strip the '5.5.5-' prefix and set the version to the correct value.
    		$db_server_info = preg_replace( '/^5\.5\.5-(.*)/', '$1', $db_server_info );
    		$db_version     = preg_replace( '/[^0-9.].*/', '', $db_server_info );
    	}

    	switch ( strtolower( $db_cap ) ) {
    		case 'collation':    // @since 2.5.0
    		case 'group_concat': // @since 2.7.0
    		case 'subqueries':   // @since 2.7.0
    			return version_compare( $db_version, '4.1', '>=' );
    		case 'set_charset':
    			return version_compare( $db_version, '5.0.7', '>=' );
    		case 'utf8mb4':      // @since 4.1.0
    			return true;
    		case 'utf8mb4_520': // @since 4.6.0
    			return version_compare( $db_version, '5.6', '>=' );
    		case 'identifier_placeholders': // @since 6.2.0
    			/*
    			 * As of WordPress 6.2, wpdb::prepare() supports identifiers via '%i',
    			 * e.g. table/field names.
    			 */
    			return true;
    	}

    	return false;
    }
    ```

[View all references](https://developer.wordpress.org/reference/files/wp-includes/class-wpdb.php/)
[View on Trac](https://core.trac.wordpress.org/browser/tags/6.9.4/src/wp-includes/class-wpdb.php#L4078)
[View on GitHub](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/class-wpdb.php#L4078-L4117)

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

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

Returns the raw version string of the database server.

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

Retrieves the database server version number.

  |

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

Determines the best charset and collation to use given a charset and collation.

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

Determines whether the database supports collation.

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

Sets the connection’s character set.

  |

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

| Version | Description | 
| [6.6.0](https://developer.wordpress.org/reference/since/6.6.0/) | The `utf8mb4` feature now always returns true. | 
| [6.2.0](https://developer.wordpress.org/reference/since/6.2.0/) | Added support for the `'identifier_placeholders'` feature. | 
| [4.6.0](https://developer.wordpress.org/reference/since/4.6.0/) | Added support for the `'utf8mb4_520'` feature. | 
| [4.1.0](https://developer.wordpress.org/reference/since/4.1.0/) | Added support for the `'utf8mb4'` feature. | 
| [2.7.0](https://developer.wordpress.org/reference/since/2.7.0/) | Introduced. |

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