我有3张桌子
表1
---------------------------
Cid | Name
-----------------------------
C1 | Customer 1
------------------------------
C2 | Customer2
------------------------------
C3 | Customer3
表2
---------------------------
Cid | ItemId
-----------------------------
C1 | i1
------------------------------
C2 | i1
-----------------------------
C1 | i2
------------------------------
C2 | i3
-----------------------------
C1 | i4
------------------------------
C2 | i4
-----------------------------
C1 | i5
------------------------------
表3
---------------------------
ItemId | price
-----------------------------
I1 | 10
------------------------------
I2 | 14
------------------------------
I3 | 15
------------------------------
I4 | 16
------------------------------
I5 | 20
------------------------------
需要一个 选择查询以获得结果
Cid | CustomerName | totalprice
----------------------------------------------------
C1 | Customer 1 | 60
----------------------------------------------------
C2 | Customer 2 | 31
----------------------------------------------------
C3 | Customer 3 | 0
答案 0 :(得分：0)
试试这个：
SELECT t1.CID,t1.NAME,SUM(t3.prize)
FROM Table1 t1
INNER JOIN Table2 t2 ON t1.CID = t2.CID
INNER JOIN on Table3 t3 ON t2.ItemID = t3.ItemID
GROUP BY t1.CID,t1.NAME