What does the `close()` method of the Mysqli Statement?

Question

Can someone tell me, when you for example update, insert, delete.. should you then close it like mysqli_stmt::close(); ? I checked PHP manual and don't understand what close() actually does.

Example:

$stmt = $dbh->prepare("SELECT `user_email` FROM `users` WHERE `user_email` = ? LIMIT 1");
$stmt->execute(array($email));
$stmt->close();

Next part of my question is, if as an example i had multiple update queries in a transaction after every execute() for each query i am executing within the transaction should i close them individually ? ... because it's a transaction not sure i need to use $stmt->close(); after each execute(); or just use one $stmt->close(); after all of them ?

Answer 1

There is no close() method for PDO, instead to close a connection you just set the database variable to null - which will close the connection.

$stmt = null;

To answer your second question, you only need to close the connection once. After you've executed all the queries you need to do on the database.