In MySQL, the given time is the nth week of the month.

In MySQL, the given time is used to Share a function written yesterday in the nth week of the month. The purpose is to find that the given time is the nth week of the month. [SQL] DELIMITER $ USE't _ girl '$ DROP FUNCTION IF exists' weekofmonth' $ CREATE DEFINER = 'root' @ 'localhost' FUNCTION 'weekofmonth' (f_datetime DATETIME) returns int (11) BEGIN -- Created by ytt. DECLARE v_result INT; DECLARE v_weekno INT; SET v_weekno = case dayofweek (f_datetime) WHEN 1 THEN 7 WHEN 2 THEN 1 WHEN 3 THEN 2 WHEN 4 THEN 3 WHEN 5 THEN 4 WHEN 6 THEN 5 WHEN 7 THEN 6 END; SET v_result = CEIL (DAYOFMONTH (DATE_SUB (f_datetime, INTERVAL v_weekno DAY)/7) + 1; RETURN v_result; END $ DELIMITER; demo result: SELECT weekofmonth (NOW () AS result; query result: result4