DROP FUNCTION function_name
This statement drops the user-defined function (UDF) named
To drop a function, you must have the
DELETE privilege for the mysql database. This is because
DROP FUNCTION removes the row from the mysql.func system table that records the function's name, type and shared library name.
For dropping a stored function, see DROP FUNCTION.
Upgrading a UDF
To upgrade the UDF's shared library, first run a DROP FUNCTION statement, then upgrade the shared library and finally run the CREATE FUNCTION statement. If you upgrade without following this process, you may crash the server.