缺少数据与群和和

我想弄明白在特定情况下的group by子句：我加入了两张应该有相同的美元金额为每张发票，所以我试图作出查询以确认没有差异。这里是表，查询和结果：缺少数据与群和和

Table A: 
Order_Number | Order_Number_Line | Amount 
1   | 1     | 80 
1   | 2     | 20 
1   | 3     | 30 
1   | 4     | 70 

Table B 

Order_Number | Order_Number_Line | Invoice_ID | Invoice_Line_Number | Amount 
1   | 1     | 1234  | 1     | 20 
1   | 2     | 1234  | 2     | 5 
1   | 3     | 1234  | 3     | 10 
1   | 4     | 1234  | 4     | 25 
1   | 1     | 1234  | 1     | 35 
1   | 2     | 1234  | 2     | 7 
1   | 3     | 1234  | 3     | 15 
1   | 4     | 1234  | 4     | 10 
1   | 1     | 1234  | 1     | 25 
1   | 2     | 1234  | 2     | 8 
1   | 3     | 1234  | 3     | 5 
1   | 4     | 1234  | 4     | 35 

Select A.Order_Number, A.Amount, B.Amount 
From Table_A as A 
Left Join (Select Order_Number, Amount From Table_B) as B 
On A.Order_Number = B.Order_Number 

Order_Number | Amount_Table_A | Amount_Table_B 
01   | 80    | 20    
01   | 80    | 5    
01   | 80    | 10    
01   | 80    | 25    
01   | 80    | 35    
01   | 80    | 7    
01   | 80    | 15   
01   | 80    | 10   
01   | 80    | 25    
01   | 80    | 8   
01   | 80    | 5   
01   | 80    | 35 
01   | 20    | 20    
01   | 20    | 5    
01   | 20    | 10    
01   | 20    | 25    
01   | 20    | 35    
01   | 20    | 7    
01   | 20    | 15   
01   | 20    | 10   
01   | 20    | 25    
01   | 20    | 8   
01   | 20    | 5   
01   | 20    | 35 
01   | 30    | 20    
01   | 30    | 5    
01   | 30    | 10    
01   | 30    | 25    
01   | 30    | 35    
01   | 30    | 7    
01   | 30    | 15   
01   | 30    | 10   
01   | 30    | 25    
01   | 30    | 8   
01   | 30    | 5   
01   | 30    | 35 
01   | 70    | 20    
01   | 70    | 5    
01   | 70    | 10    
01   | 70    | 25    
01   | 70    | 35    
01   | 70    | 7    
01   | 70    | 15   
01   | 70    | 10   
01   | 70    | 25    
01   | 70    | 8   
01   | 70    | 5   
01   | 70    | 35

我试着用分组，但是只得到了每个表的第一个量的记录：

Select A.Order_Number, A.Amount, B.Amount 
From Table_A as A 
Left Join (Select Order_Number, Amount From Table_B) as B 
On A.Order_Number = B.Order_Number 
Group By A.Order_Number 

Invoice_ID | Amount_Table_A | Amount_Table_B | 
01   | 80    | 20    |

我尝试添加的总和（）子句每个量在SELECT语句的属性，得到了各重复记录的总和：

Select A.Order_Number, sum(A.Amount), sum(B.Amount) 
From Table_A as A 
Left Join (Select Order_Number, Amount From Table_B) as B 
On A.Order_Number = B.Order_Number 
Group By A.Order_Number 

Invoice_ID | Amount_Table_A | Amount_Table_B | 
01   | 2400   | 800    |

请问有什么可以修改此查询，以显示真正的价值？预期值为：

Invoice_ID | Amount_Table_A | Amount_Table_B | 
01   | 200    | 200    |

请注意，这是一个过于简化的数据集。真正的表有超过一百万条记录，我需要确保Invoice_ID在两个表中总计相同。

非常感谢你！

来源

2017-09-14 Christián De Achával

您能否请您发布表A和表B中的第一个10-20条记录，以及您需要的10-20条记录计算所需的输出。这将有助于更好地了解你需要什么。 –

我刚刚编辑了问题，以便您可以访问数据集。期望的输出是每个表的期望值：200。 –

试试这个，让我知道这是否适合你。

SELECT 
    A.Order_Number, A.Amount AS A_Amount, B.Amount AS B_Amount 
FROM 
    (SELECT 
     Order_Number, SUM(Amount) AS Amount 
    FROM 
     A 
    GROUP BY Order_Number) A 
     JOIN 
    (SELECT 
     Order_Number, SUM(Amount) AS Amount 
    FROM 
     B 
    GROUP BY Order_Number) B ON A.Order_Number = B.Order_Number

来源

2017-09-14 19:16:59

它工作了！是否有推荐的文献来理解查询的工作方式？我从来没有这样建立过 –

你很近，试试这个。这并不是100％清楚你想要做什么，但我希望这有助于。看起来你在加入时没有足够的选择性。

Select A.Order_Number, SUM(A.Amount), SUM(B.Amount) 
From Table_A as A 
Left Join Table_B as B 
On A.Order_Number = B.Order_Number AND A.Order_Line_Number = B.Order_Line_Number 
Group By A.Order_Number

来源

2017-09-14 19:12:51 pucky124

这几乎成功！我正在编辑问题并添加您的修复程序。 B.Amount出来了，但A.Amount出来的3X是正确的A.Amount。我的目标是运行一个查询，它将为我的所有Order_Numbers显示A.Amount和B.Amount。在这个例子中，我只使用了1个订单号，但我有数千个订单号。我想确保表A和B中的数量是同步的。 –

缺少数据与群和和

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