在mysql中使用子查詢的結果

我的代碼看起來像這樣。

select (select count(*) from tbl1 group by field) as result1, 
     (select count(*) from tbl2 group by field) as result2, 
     (select count(*) from tbl3 group by field) as result3, 
     result1 + result2 - result3 as total1, 
     result1 + result2 as total2 
from tbl4 ;

一些建議直接添加子查詢。

(select count(*)*....) as result1 + (select count(*)*....) as result2

但我認爲它不想我需要，bcoz我也需要在結果中顯示/維護result1的值。

有沒有人可以幫助我，我非常需要這個工作，我感謝每一個幫助。

在此先感謝。

來源

2012-07-13 avien

得到的表你需要什麼，請表明，因爲你需要什麼，不清楚 – 2012-07-13 05:56:55

result：如果result1爲3，result2爲2，result3爲4，那麼total1將爲1（result1 + result2 - result3） – avien 2012-07-13 06:00:36

@avien：那麼你的查詢出了什麼問題？ – 2012-07-13 06:02:38

你將不得不包裹查詢子查詢中，以便能夠訪問別名的列名：

SELECT a.result1 + a.result2 - a.result3 AS total1, 
     a.result1 + a.result2 AS total2 
    FROM (
      select (select count(*) from tbl1 group by field) as result1, 
        (select count(*) from tbl2 group by field) as result2, 
        (select count(*) from tbl3 group by field) as result3 
     ) a

但是，這實際上是一個更好的解決方案：

SELECT a.cnt + b.cnt - c.cnt AS total1, 
      a.cnt + b.cnt AS total2 
     FROM (SELECT COUNT(*) cnt FROM tbl1 GROUP BY field) a 
CROSS JOIN (SELECT COUNT(*) cnt FROM tbl2 GROUP BY field) b 
CROSS JOIN (SELECT COUNT(*) cnt FROM tbl3 GROUP BY field) c

來源

2012-07-13 06:02:49

我忘了告訴我所有的子查詢取決於我的我的tbl4這樣（select（count（*）from tbl1 group by field where tbl1.field = tbl4.field） – avien 2012-07-13 06:06:38

假設你子查詢將返回一個集合。因此，只要使用以下---

SELECT column1, column2, column3 FROM table1 WHERE column3 IN (SELECT column3 FROM table2 WHERE condition);

來源

2012-07-13 06:05:33

select count1, count2, count3, 
    count1+count2-count3 as total1, count1+count2 as total2 
    from tbl4 
inner join 
    (select count(*) as count1,name from tbl1 group by name)as result1 
on tbl4.name=result1.name 
inner join 
    (select count(*)as count2,name from tbl2 group by name) as result2 
on tbl4.name=result2.name 
inner join 
    (select count(*)as count3,name from tbl3 group by name) as result3 
on tbl4.name=result3.name

來源

2012-07-13 06:16:19 sel

請嘗試此查詢，讓我知道

select result1.cnt,result2.cnt,result2.cnt,result1.cnt + 
    result2.cnt - result3.cnt as total1, 
    result1.cnt + result2.cnt as total2 
    from 
(select field,COUNT(*) cnt from tbl1 group by field) as result1 
    join 
(select field,COUNT(*) cnt from tbl2 group by field) as result2 
on result1.field=result2.field 
join 
(select field,COUNT(*) cnt from tbl3 group by field) as result3 
on result3.field=result2.field 
join tbl4 
on tbl1.field = tbl4.field

來源

2012-07-13 06:30:34

在mysql中使用子查詢的結果

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