long with all privileges specific to the
procedure. You must have the ALTER ROUTINE privilege for the routine. If the
automatic_sp_privileges server system variable is set, that privilege and
EXECUTE are granted automatically to the routine creator - see Stored Routine
Privileges.

The IF EXISTS clause is a MySQL/MariaDB extension. It prevents an error from
occurring if the procedure or function does not exist. A NOTE is produced that
can be viewed with SHOW WARNINGS.

While this statement takes effect immediately, threads which are executing a
procedure can continue execution.

Examples
--------

DROP PROCEDURE simpleproc;

IF EXISTS:

DROP PROCEDURE simpleproc;
ERROR 1305 (42000): PROCEDURE test.simpleproc does not exist

DROP PROCEDURE IF EXISTS simpleproc;
Query OK, 0 rows affected, 1 warning (0.00 sec)

SHOW WARNINGS;
+-------+------+------------------------------------------+
| Level | Code | Message                                  |
+-------+------+------------------------------------------+
| Note  | 1305 | PROCEDURE test.simpleproc does not exist |
+-------+------+------------------------------------------+

URL: https://mariadb.com/kb/en/drop-procedure/https://mariadb.com/kb/en/drop-procedure/