mysql - 需要通过更改参数来循环 MySql 查询

Question

我是 mysql 脚本的新手，我想通过将 00:00:00 时间增加到 30 分钟来执行此查询。

像这样的

Select count(*) 
FROM ctrdb.CTR_LINE_ITEM 
where LOAD_DATE BETWEEN '2016-05-18 00:00:00' AND '2016-05-18 00:30:00' 
order by load_date;

Select count(*) 
FROM ctrdb.CTR_LINE_ITEM 
where LOAD_DATE BETWEEN '2016-05-18 00:30:00' AND '2016-05-18 00:60:00' 
order by load_date;

你们能帮帮我吗？

Answer 1

如果你想在 mysql 中实现这个并且想为每个查询获得单独的结果集 那么您需要使用存储过程在循环中运行您的查询。

在 mysql 中读取循环 http://www.mysqltutorial.org/stored-procedures-loop.aspx

或者没有多个查询那么你也可以使用union

    DELIMITER $$
CREATE PROCEDURE getdata()
 BEGIN
 DECLARE x  INT;

 DECLARE maximum INT; # you can use date as well
 DECLARE startdate  DATE;
 DECLARE enddate  DATE;

 SET x =0;

 SET maximum = 10;
 SET startdate =   '2016-05-18 00:00:00';


 loop_label:  LOOP
    IF  x > 10 THEN 
        LEAVE  loop_label;
    END  IF;
    SET  x = x + 1;
    SET enddate =   startdate   + INTERVAL 30 MINUTE;
    Select count(*) ,startdate
    FROM ctrdb.CTR_LINE_ITEM 
    where LOAD_DATE BETWEEN '2016-05-18 00:00:00' AND '2016-05-18 00:30:00' 
    order by load_date;
    SET startdate =   startdate   + INTERVAL 30 MINUTE;

END LOOP; 
END $$

DELIMITER ;