存储过程实现循环

BEGIN
    DECLARE
        count INT DEFAULT 11;
    DECLARE 
        maxtime VARCHAR(50) DEFAULT DATE_FORMAT( now(),'%Y-%m-%d ');
    DECLARE 
        maxtimenew VARCHAR(50) DEFAULT null;

WHILE count < 15 DO

    #sql区
    #concat String拼接int
    set maxtimenew=concat(maxtime,count);
    SELECT maxtimenew;
    SELECT COUNT(*) as '登入用户数量' FROM log_login t WHERE DATE_FORMAT(t.create_time,'%Y-%m-%d %H')=maxtimenew;


SET count = count + 1;


END
WHILE;

SELECT
    count;


END

转换时间格式

DATE_FORMAT(now(),'%Y-%m-%d %H')