複数のテーブルから選択する

Question

テーブルB、テーブルc。

表AのID、COL1

ID COL1 
1  abc 
2  bcd 

表B、表C、iはIDを選択するために今

ID col3 
1 qwe 
1 tre 
1 uid 
2 jkj 
2 jwekj 

COL4 ID、必要たCOL2、COL3

col2 col3 
bcc abc 
acc bcd 

を有しています、COL1、COL2、カウント（表CのID）。サンプル出力は

ID COL1 COL2 CNT 
1 abc bcc 3 
2 bcd acc 2 

となります。誰でも私を助けてくれますか？表AおよびBは、CO11およびCOL3を使用して結合される。

Answer 1

select a.id 
,  max(a.col1) 
,  avg(b.col2) 
,  count(distinct c.ID) 
from TableA a 
join TableA b 
on  a.col1 = b.col3 
left join 
     TableC c 
on  c.id = a.id 
group by 
     a.id 

Answer 2

表A &表CをIDでカウントしてカウントしてみませんか？たぶん

SELECT TableA.ID, TableA.COL1, TableB.COL2, COUNT(TableC.*) 
FROM TableA 
INNER JOIN TableB ON TableB.COL3 = TableA.COL1 
INNER JOIN TableC ON TableC.ID = TableA.ID 
GROUP BY TableA.ID, TableA.COL1, TableB.COL2 
ORDER BY TableA.ID, TableA.COL1, TableB.Col2 

Answer 3

SELECT A.ID, A.COL1, B.COL2, (SELECT COUNT(C.ID) FROM C) AS CNT 
FROM A INNER JOIN B ON A.COL1=B.COL3 

Answer 4

このような何か：

SELECT 
    TableA.COL1, 
    TableB.col2, 
    (
     SELECT 
      COUNT(*) 
     FROM 
      TableC 
     WHERE 
      TableC.ID=TableA.ID 
    ) 
FROM 
    TableA 
    JOIN TableB 
     ON TableA.COL1=TableB.col3 

Answer 5

Select 
    a.Id, a.col1, b.col2, count(c.*) As Cnt 
From A as a 
Inner Join B as b on a.col1 = b.col3 
Inner Join C as c on a.Id = c.Id 
Group By a.Id, a.col1, b.col2 

Answer 6

declare @A table(ID int, col1 varchar(50)) 
declare @B table(col2 varchar(50), col3 varchar(50)) 
declare @C table(ID int, col4 varchar(50)) 

INSERT INTO @A(ID, col1) values(1, 'abc') 
INSERT INTO @A(ID, col1) values(2, 'bcd') 

INSERT INTO @B(col2, col3) values('bcc' , 'abc') 
INSERT INTO @B(col2, col3) values('acc' , 'bcd') 

INSERT INTO @C(ID, col4) values('1' , 'qwe') 
INSERT INTO @C(ID, col4) values('1' , 'tre') 
INSERT INTO @C(ID, col4) values('1' , 'uid') 
INSERT INTO @C(ID, col4) values('2' , 'jkj') 
INSERT INTO @C(ID, col4) values('2' , 'jwekj') 


-- The query 
SELECT a.ID, a.col1, b.col2, (SELECT COUNT(c.ID) FROM @C c WHERE c.ID = a.ID) CNT 
FROM @A a join @b b ON a.col1 = b.col3 

Answer 7

select A.iD, A.Col1,B.col2, 
     (select count(*) from tableC C where C.id=A.ID) as cnt 
from tableA A join tableB B on A.col1=b.col3 

Answer 8

select A.ID, A.Col1, B.Col2, Count(*) AS Cnt 
from A 
inner join B ON B.Col3 = A.Col1 
left join C ON C.ID = A.ID 
Group By A.ID, A.Col1, B.Col2