wpdb::close()
Closes the current database connection.
Return
(bool) True if the connection was successfully closed, false if it wasn't, or if the connection doesn't exist.
Source
File: wp-includes/wp-db.php
public function close() {
		if ( ! $this->dbh ) {
			return false;
		}
		if ( $this->use_mysqli ) {
			$closed = mysqli_close( $this->dbh );
		} else {
			$closed = mysql_close( $this->dbh );
		}
		if ( $closed ) {
			$this->dbh           = null;
			$this->ready         = false;
			$this->has_connected = false;
		}
		return $closed;
	}  Changelog
| Version | Description | 
|---|---|
| 4.5.0 | Introduced. | 
    © 2003–2021 WordPress Foundation
Licensed under the GNU GPLv2+ License.
    https://developer.wordpress.org/reference/classes/wpdb/close