Question

我想问一下如何加入这些查询？第一个是从我的桌面日历中获取的，当时所有星期一都会被取出，而第一个星期一则是。

SELECT 
calender As Firsts
FROM
calender
WHERE
calender >= '2017-03-01'
    AND calender <= '2017-03-31'
    AND DAYOFWEEK(calender) = 2
    OR calender = '2017-03-01' 
GROUP BY calender;

然后我从我的桌面日历中取出所有星期日和本月的最后一天。

SELECT 
calender As Lasted
FROM
calender
WHERE
calender.calender >= '2017-03-01'
    AND calender.calender <= '2017-03-31'
    AND DAYOFWEEK(calender) = 1
    OR calender = '2017-03-31'
GROUP BY calender;

我想要像这样的输出

First | Last
2017-03-01  | 2017-03-05
2017-03-06  | 2017-03-12
2017-03-13  | 2017-03-19
2017-03-20  | 2017-03-26
2017-03-27  | 2017-03-31

我尝试使用子查询然后错误1242子查询返回超过1行，是否可以加入这两个查询？

由于

Answer 1

这是假设您在表calendar

上有主键

SELECT 
   (SELECT calender 
    FROM calendar ic 
    WHERE ic.primary_key = oc.primary_key 
     AND DAYOFWEEK(ic.calender) = 2
    GROUP BY calendar) As First,
   (SELECT calender 
    FROM calendar ic 
    WHERE ic.primary_key = oc.primary_key 
     AND DAYOFWEEK(ic.calender) = 1
    GROUP BY calendar) As Last,
FROM 
  calender oc
WHERE
  calender >= '2017-03-01'
 AND calender <= '2017-03-31'
 OR calender = '2017-03-01';

Answer 2

一种方法可能是

SELECT ( SELECT calender FROM calender WHERE
    calender >= '2017-03-01'
        AND calender <= '2017-03-31'
        AND DAYOFWEEK(calender) = 2
        OR calender = '2017-03-01' 
        GROUP BY calender) As Firsts, ( SELECT calender FROM calender WHERE
    calender.calender >= '2017-03-01'
        AND calender.calender <= '2017-03-31'
        AND DAYOFWEEK(calender) = 1
        OR calender = '2017-03-31'
        GROUP BY calender
    ) As Last FROM calender

Answer 3

SELECT 
startdate.Start, Enddate.End
FROM
(SELECT 
    @counter0:=@counter0 + 1 AS ID, calender AS Selesai
FROM
    calender, (SELECT @counter0:=0) T
WHERE
    calender BETWEEN startdate AND enddate
        AND DAYOFWEEK(calender) = 1
        OR calender = enddate) Enddate
    JOIN
(SELECT 
    @counter:=@counter + 1 AS ID, calender AS Mulai
FROM
    calender, (SELECT @counter:=0) T
WHERE
    calender BETWEEN startdate AND enddate
        AND DAYOFWEEK(calender) = 2
        OR calender = startdate) Startdate ON Startdate.ID = Enddate.ID

这是我用row_number（）解决问题的方法，谢谢我最好的朋友#Lun_Ng

mysql - 在一个表中选择查询连接

3 个答案: