Java 用另一个表中的金额总和减去一个表中的金额总和

我得到了错误的sql结果，该结果的金额为双负值

我想用另一张表的金额总和减去一张表的金额总和

这是

bet\u tbl

（第一个表）数据。只勾选下注号码“11”。赌注总额为2000英镑。见下文

select 
  `bet_Number`, 
  SUM(bet_tbl.`Amount`) - SUM(recover_tbl.`Amount`) AS 'AMOUNT'
from bet_tbl, recover_tbl
WHERE bet_tbl.status= recover_tbl.status
  AND bet_tbl.`bet_Date`=recover_tbl.`recover_Date` 
  AND bet_tbl.status = '0'
  AND bet_tbl.`bet_Date`='2013-07-02'
GROUP BY bet_tbl.`bet_Number`

bet\u tbl

：

这是

恢复\u tbl

（第二个表）数据。

recover\u tbl

的金额总和为100

见下文

select 
  `bet_Number`, 
  SUM(bet_tbl.`Amount`) - SUM(recover_tbl.`Amount`) AS 'AMOUNT'
from bet_tbl, recover_tbl
WHERE bet_tbl.status= recover_tbl.status
  AND bet_tbl.`bet_Date`=recover_tbl.`recover_Date` 
  AND bet_tbl.status = '0'
  AND bet_tbl.`bet_Date`='2013-07-02'
GROUP BY bet_tbl.`bet_Number`

最后的结果是我想得到减去

bet\u tbl.amount

和

recover\u tbl后的金额总和。amount

是1900。但是当我运行下面的查询时，我得到了1800。请参见下文

select 
  `bet_Number`, 
  SUM(bet_tbl.`Amount`) - SUM(recover_tbl.`Amount`) AS 'AMOUNT'
from bet_tbl, recover_tbl
WHERE bet_tbl.status= recover_tbl.status
  AND bet_tbl.`bet_Date`=recover_tbl.`recover_Date` 
  AND bet_tbl.status = '0'
  AND bet_tbl.`bet_Date`='2013-07-02'
GROUP BY bet_tbl.`bet_Number`

以下是运行查询后的结果

[结果]:

---

我找不到哪里出错了。我陷入了困境，需要帮助。谢谢你的建议和回答。

如果你只想下注。下注号码='11'，你在哪里找不到它

select 
  `bet_Number`, 
  SUM(bet_tbl.`Amount`) - SUM(recover_tbl.`Amount`) AS 'AMOUNT'
from bet_tbl, recover_tbl
WHERE bet_tbl.status= recover_tbl.status
  AND bet_tbl.`bet_Date`=recover_tbl.`recover_Date` 
  AND bet_tbl.status = '0'
  AND bet_tbl.`bet_Date`='2013-07-02'
  and bet_tbl.bet_Number = '11'
GROUP BY bet_tbl.`bet_Number`

---

尝试在

bet\u Number

或

Max（bet\u Number）

前面添加

Distinct

子句，这样做将产生1800个。这是因为聚合是在加入后执行的。 你知道有两个记录，11个下注号码，1000个金额。因此，与另一个表连接将生成两条记录

bet_number           bet_tbl.Amount            recover_tbl.Amount
11                   1000                      100
11                   1000                      100

现在把它聚合起来就可以了

bet_number           SUM(bet_tbl.Amount)       SUM(recover_tbl.Amount)
11                   2000                      200

因此结果是2000-200=1800

在使用recover\u tbl减去金额之前，需要在表bet\u tbl中进行聚合。差不多

SELECT 
T1.*
FROM
(
    select 
    bet_number,
    SUM(Amount) Amount
    FROM
    bet_tbl
    WHERE 
    bet_tbl.status = '0'
    bet_tbl.bet_Date ='2013-07-02'
    Group by bet_number
) T1
JOIN recover_tbl T2
ON T1.bet_number = T2.recover_number

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无法查看您的表格或结果，请担心kevinm。当我发布此问题时，我上传的图片失败