在mysql查詢中計算余額總和

Question

我正在嘗試生成客戶余額未結報告。

我有兩個表： customer和transaction ：

顧客

custid| custname
------+------------
1     | abc
2     | xyz 
3     | ben    
4     | angel

交易

tid| customerid  | amount
---+-------------+-------
1  | 1           | 100
2  | 4           | 300
3  | 2           | 130
4  | 2           | 500
5  | 3           | 100
6  | 1           | 35
7  | 4           | 104
8  | 1           | 25
9  | 3           | 50

我想得到這樣的結果：

Custname  | balance
----------+--------
abc       | 160
xyz       | 630
ben       | 150   
angel     | 404

Answer 1

SELECT a.custname as custname 
     , sum(b.amount) as balance 
  from customer a
     , transaction b 
 where a.custid = b.customerid