MySQL in PHP gives error, MySQL in phpmyadmin does not - php

Question

I want to truncate a table via PHP. It has some foreign keys, so I use the little trick where I set my foreign key check to zero:
$query_truncate_extension = "SET FOREIGN_KEY_CHECKS = 0; TRUNCATE TABLE extension; SET FOREIGN_KEY_CHECKS = 1;";
When I execute the script, the mysqli_error() gives me the following error:
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'TRUNCATE TABLE extension; SET FOREIGN_KEY_CHECKS = 1' at line 1
So my table doesn't get truncated at all. But the weird thing is when I put this exact same query in the SQL-query section in phpmyadmin, it doesn't throw an error at all and my table is empty afterwards.
So my question is: why does this code gives an error in PHP, but not in phpmyadmin and how do I solve this?
Thanks in advance!

Answer 1

If you wan to run multiple queries in one call then you need to use
mysqli_multi_query()
This is a function allows to run one or multiple queries which are concatenated by a semicolon.
To retrieve the resultset from the first query you can use mysqli_use_result() or mysqli_store_result(). All subsequent query results can be processed using mysqli_more_results() and mysqli_next_result().
You can read more detail here.
http://php.net/manual/en/mysqli.multi-query.php
--------- Example Program at the link above -------------
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
$query = "SELECT CURRENT_USER();";
$query .= "SELECT Name FROM City ORDER BY ID LIMIT 20, 5";
/* execute multi query */
if ($mysqli->multi_query($query)) {
do {
/* store first result set */
if ($result = $mysqli->store_result()) {
while ($row = $result->fetch_row()) {
printf("%s\n", $row[0]);
}
$result->free();
}
/* print divider */
if ($mysqli->more_results()) {
printf("-----------------\n");
}
} while ($mysqli->next_result());
}
/* close connection */
$mysqli->close();
You can change it according to your requirement.

Answer 2

Use single query in single call like
$query_truncate_extension = "SET FOREIGN_KEY_CHECKS = 0"