DROP FUNCTION
Drop a function.
Syntax​
DROP FUNCTION [IF EXISTS] <function_name>
Examples​
mysql> CREATE FUNCTION IF NOT EXISTS isnotempty AS (p) -> not(isnull(p)) DESC = 'This is a description';
mysql> SHOW FUNCTIONS LIKE 'isnotempty';
+------------+------------+--------------+----------------+-----------------------+
| name | is_builtin | is_aggregate | definition | description |
+------------+------------+--------------+----------------+-----------------------+
| isnotempty | 0 | 0 | not(isnull(p)) | This is a description |
+------------+------------+--------------+----------------+-----------------------+
mysql> DROP FUNCTION IF EXISTS isnotempty;
mysql> SHOW FUNCTIONS LIKE 'isnotempty';