如何使用IF STATE MySQL实现WHILE LOOP？
以下是使用IF语句实现MySQLWHILELOOP的示例。我们正在使用存储过程
以下是创建我们的存储过程的查询：
DELIMITER // create procedure sp_getDaysDemo() -> BEGIN -> SELECT MONTH(CURDATE()) INTO @current_month; -> SELECT MONTHNAME(CURDATE()) INTO @current_monthname; -> SELECT DAY(LAST_DAY(CURDATE())) INTO @total_numberofdays; -> SELECT CAST(DATE_FORMAT(NOW() ,'%Y-%m-01') as DATE)INTO @check_weekday; -> SELECT DAY(@check_weekday) INTO @check_day; -> SET @count_days = 0; -> SET @workdays = 0; -> -> WHILE(@count_days < @total_numberofdays) DO -> IF (WEEKDAY(@check_weekday) < 5) THEN -> SET @workdays = @workdays+1; -> END IF; -> SET @count_days = @count_days+1; -> SELECT ADDDATE(@check_weekday, INTERVAL 1 DAY) INTO @check_weekday; -> END WHILE; -> -> select @current_month,@current_monthname,@total_numberofdays,@check_weekday,@check_day; -> END -> -> // delimiter ;
使用CALL命令调用存储过程。语法如下：
CALL yourStoredProcedureName();
现在，您可以使用以下查询调用存储过程：
call sp_getDaysDemo();
以下是输出：
+----------------+--------------------+---------------------+----------------+------------+ | @current_month | @current_monthname | @total_numberofdays | @check_weekday | @check_day | +----------------+--------------------+---------------------+----------------+------------+ | 1 | January | 31 | 2019-02-01 | 1 | +----------------+--------------------+---------------------+----------------+------------+ 1 row in set (0.00 sec)