MySQL 5.7 Release Notes
DROP EVENT [IF EXISTS] event_name
This statement drops the event named
event_name. The event immediately
ceases being active, and is deleted completely from the server.
If the event does not exist, the error ERROR 1517
(HY000): Unknown event
'event_name' results. You
can override this and cause the statement to generate a warning
for nonexistent events instead using IF EXISTS.
This statement requires the EVENT
privilege for the schema to which the event to be dropped belongs.