Question

我在DB2中有以下查询但是没有工作，问题是max函数但是我不确定如何解决它。

SELECT CAR.VI max(CAR.ID),
TU.SOLD 
FROM P.CAR CAR, A.TU TU WHERE CAR.VI = TU.VI

'Table1'                                                              ' VI:     USER:  DATE:      DATE2:     STATUS:   ID'
' 2T1BU4  DEALER 2012-10-15 2012-10-15 CER       1 '
' 2T1BU4  DEALER 2012-10-15 2012-10-15 CER       2 '
' 2T1BU3  DEALER 2012-10-15 2012-10-15 DRA       1 '


' VI:     SOLD:'
' 2T1BU4  Y' 
' 2T1BU3  N'

我希望从查询中收到的内容如下：

    ' VI:     USER:  DATE:      DATE2:     STATUS:   ID  SOLD'
' 2T1BU4  DEALER 2012-10-15 2012-10-15 CER       2   Y   '
' 2T1BU3  DEALER 2012-10-15 2012-10-15 DRA       1   N   '

我想获得具有最大ID

的VI

Answer 1

你没有提供很多细节，但我猜你想要这个：

SELECT CAR.VI, max(CAR.ID), TU.SOLD 
FROM P.CAR CAR
INNER JOIN A.TU TU 
    ON CAR.VI = TU.VI
GROUP BY CAR.VI, TU.SOLD

或者您可以使用子查询：

select c1.vi, c1.id, tu.sold
from 
(
    select max(id) id, vi
    from P.CAR
    group by vi
) c1
inner join A.TU TU 
    on c1.VI = TU.VI

Answer 2

使用公用表表达式的变体：

with cte (vi, id) as 
(SELECT vi, max(ID)
 FROM P.CAR
 group by vi)
select cte.vi, cte.id, tu.sold
from cte INNER JOIN A.TU TU 
ON cte.VI = TU.VI

Answer 3

我不是100％确定你想要什么，但听起来你想要每个VI都有MAX（ID）的记录。你需要做这样的事情：

SELECT C1.VI, C1.ID, TU.SOLD FROM P.CAR CAR C1, A.TU TU WHERE C1.VI = TU.VI
WHERE C1.ID = (SELECT MAX(C2.VI) FROM P.CAR C2 WHERE C1.VI = C2.VI)

DB2 sql Max记录功能

3 个答案: