wp-includes/class-wpdb.php:4073Determines whether the database server is at least the required minimum version.
WP_Error|null public function check_database_version() { global $required_mysql_version; $wp_version = wp_get_wp_version(); // Make sure the server has the required MySQL version. if ( version_compare( $this->db_version(), $required_mysql_version, '<' ) ) { /* translators: 1: WordPress version number, 2: Minimum required MySQL version number. */ return new WP_Error( 'database_version', sprintf( __( '<strong>Error:</strong> WordPress %1$s requires MySQL %2$s or higher' ), $wp_version, $required_mysql_version ) ); } return null; }Introduced in 2.5.0. One change between 6.7.7 and 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
void|WP_Error to WP_Error|null.verified against sourcesrc/wp-includes/class-wpdb.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.