结合的MySQL查询

我苦苦寻找的远离这2个查询组合...香港专业教育学院试图subquerys，连接，联合和有没有运气:(结合的MySQL查询

查询

SELECT DATE(crtdtime) AS cntldate, sd_class, COUNT(crtdtime) AS created 
FROM master 
WHERE DATE(crtdtime) = '2011-11-16' 
GROUP BY cntldate, sd_class

将会产生

+------------+----------+---------+ 
| cntldate | sd_class | created | 
+------------+----------+---------+ 
| 2011-11-16 | CUST  | 2226 | 
| 2011-11-16 | NET  |  238 | 
+------------+----------+---------+

查询乙

SELECT DATE(rstdtime) AS cntldate, sd_class, COUNT(rstdtime) AS restored 
FROM master 
WHERE DATE(rstdtime) = '2011-11-16' 
GROUP BY cntldate, sd_class

将会产生

+------------+----------+----------+ 
| cntldate | sd_class | restored | 
+------------+----------+----------+ 
| 2011-11-16 | CUST  |  2315 | 
| 2011-11-16 | NET  |  221 | 
+------------+----------+----------+

但想最终的结果是...

+------------+----------+---------+----------+ 
| cntldate | sd_class | created | restored | 
+------------+----------+---------+----------+ 
| 2011-11-16 | CUST  | 2226 |  2315 | 
| 2011-11-16 | NET  |  238 |  221 | 
+------------+----------+---------+----------+

将不胜感激任何帮助。

谢谢。

来源

2011-11-18 mybigman

使用

SELECT C.cntldate, C.sd_class, C.created, R.restored 
FROM 
(
SELECT DATE(crtdtime) AS cntldate, sd_class, COUNT(crtdtime) AS created 
FROM master 
GROUP BY cntldate, sd_class 
) C 
INNER JOIN 
(
SELECT DATE(rstdtime) AS cntldate, sd_class, COUNT(rstdtime) AS restored 
FROM master 
GROUP BY cntldate, sd_class 
) R 
ON R.cntldate = C.cntldate AND R.sd_class = C.sd_class 
WHERE C.cntldate = '2011-11-16' AND R.cntldate = '2011-11-16'

来源

2011-11-18 01:06:43 Yahia

谢谢大家对你的帮助是非常非常感谢，并与** Yahia的**版本，因为它给了我最大的灵活性。 – mybigman

@mybigman欢迎您:-)请不要忘记将upvote/mark标记为已接受任何有帮助的答案（请参阅http://meta.stackexchange.com/questions/5234/how-does-accepting-an-回答工作）。 – Yahia

如何

select q1.cntldate, q1.sd_class, q1.created, q2.restored 
    from (
    SELECT DATE(crtdtime) AS cntldate, sd_class, COUNT(crtdtime) AS created 
     FROM master 
     WHERE DATE(crtdtime) = '2011-11-16' 
     GROUP BY cntldate, sd_class 
    ) q1 
    inner join (
     SELECT DATE(rstdtime) AS cntldate, sd_class, COUNT(rstdtime) AS restored 
     FROM master 
     WHERE DATE(rstdtime) = '2011-11-16' 
     GROUP BY cntldate, sd_class 
) q2 
     on q1.cntldate=q2.cntldate and q1.sdclass = q2.sdclass

这是Postgres的语法的，所以可能会发挥它得到它与MySQL

来源

2011-11-18 01:08:48

我相信这将工作运行：

SELECT DATE(m1.crtdtime) AS cntldate, 
m1.sd_class, 
COUNT(m1.crtdtime) AS created , 
(
    SELECT COUNT(m2.rstdtime) 
    FROM master m2 
    WHERE DATE(m2.rstdtime) = DATE(m1.rstdtime) 
    and m2.sd_class=m1.sd_class 
) as restored 
FROM master m1 
WHERE DATE(crtdtime) = '2011-11-16' 
GROUP BY cntldate, sd_class

来源

2011-11-18 01:10:24 Icarus

一种可能的方式

SELECT DATE(crtdtime) AS cntldate, 
    sd_class, 
    sum(DATE(crtdtime) = '2011-11-16') AS created 
    sum(DATE(rstdtime) = '2011-11-16') AS restored 
FROM master 
WHERE DATE(crtdtime) = '2011-11-16' or DATE(rstdtime) = '2011-11-16' 
GROUP BY cntldate, sd_class

来源

2011-11-18 01:14:02

我只是在那里......但是，如果且仅当单一日期才有效...... – DRapp

它实际上并不难（一旦你已经做了一段时间）。使用SUM（IF（）），如...

SELECT 
     date(if(date(ctrdtime) = '2011-11-16', ctrdtime, rstdtime)) as CntlDate, 
     sd_class, 
     sum(if(date(ctrdtime) = '2011-11-16', 1, 0)) as CreatedCount, 
     sum(if(date(rstdtime) = '2011-11-16', 1, 0)) as RestoredCount 
    FROM 
     master 
    WHERE 
     DATE(crtdtime) = '2011-11-16' 
     OR DATE(rstdtime) = '2011-11-16' 
    GROUP BY 
     1, 2

这也将工作，如果你扩展了双方建立和恢复的日期范围...

来源

2011-11-18 01:17:36 DRapp

结合的MySQL查询

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