wpdb::has_cap( string $db_cap )

Determine if a database supports a particular feature.


Description Description

See also See also


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Parameters Parameters

$db_cap

(string) (Required) The feature to check for. Accepts 'collation', 'group_concat', 'subqueries', 'set_charset', 'utf8mb4', or 'utf8mb4_520'.


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Return Return

(int|false) Whether the database feature is supported, false otherwise.


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Source Source

File: wp-includes/wp-db.php

	public function has_cap( $db_cap ) {
		$version = $this->db_version();

		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( $version, '4.1', '>=' );
			case 'set_charset' :
				return version_compare( $version, '5.0.7', '>=' );
			case 'utf8mb4' :      // @since 4.1.0
				if ( version_compare( $version, '5.5.3', '<' ) ) {
					return false;
				}
				if ( $this->use_mysqli ) {
					$client_version = mysqli_get_client_info();
				} else {
					$client_version = mysql_get_client_info();
				}

				/*
				 * libmysql has supported utf8mb4 since 5.5.3, same as the MySQL server.
				 * mysqlnd has supported utf8mb4 since 5.0.9.
				 */
				if ( false !== strpos( $client_version, 'mysqlnd' ) ) {
					$client_version = preg_replace( '/^\D+([\d.]+).*/', '$1', $client_version );
					return version_compare( $client_version, '5.0.9', '>=' );
				} else {
					return version_compare( $client_version, '5.5.3', '>=' );
				}
			case 'utf8mb4_520' : // @since 4.6.0
				return version_compare( $version, '5.6', '>=' );
		}

		return false;
	}

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Changelog Changelog

Changelog
Version Description
4.6.0 Added support for the 'utf8mb4_520' feature.
4.1.0 Added support for the 'utf8mb4' feature.
2.7.0 Introduced.


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