如何组合这些查询？

Question

我有5个查询,我想加入.基本上他们所做的是通过数据库并选择租户支付了多少,以及租户根据他或她多久收费而欠多少钱.

我有四类
费用<30天
收费<60 AND> = 30天
收费<90 AND> = 60天
收费> 90天

我知道如何分别获得所有这些价值,但我怎样才能将它们合并在一起,加上租户支付的金额？

以下是我的疑问:
租户支付的金额

SELECT TransactionCode, TenantID, SUM(Amount) AS Paid FROM tblTransaction
WHERE Amount > 0
GROUP BY TransactionCode, TenantID

收费不到30天

SELECT TransactionCode, TenantID, SUM(Amount) AS ChargedCurrent FROM tblTransaction
WHERE Amount < 0 AND TransactionDate > DATEADD("dd", -30, GETDATE())
GROUP BY TransactionCode, TenantID

收费不到60天,但超过29天

SELECT TransactionCode, TenantID, SUM(Amount) AS ChargedOver30 FROM tblTransaction
WHERE Amount < 0 AND TransactionDate > DATEADD("dd", -60, GETDATE()) AND TransactionDate <= DATEADD("dd", -30, GETDATE())
GROUP BY TransactionCode, TenantID

收费不到90天,但超过59天

SELECT TransactionCode, TenantID, SUM(Amount) AS ChargedOver60 FROM tblTransaction
WHERE Amount < 0 AND TransactionDate > DATEADD("dd", -90, GETDATE()) AND TransactionDate <= DATEADD("dd", -60, GETDATE())
GROUP BY TransactionCode, TenantID

收费超过89天

SELECT TransactionCode, TenantID, SUM(Amount) AS ChargedOver90 FROM tblTransaction
WHERE Amount < 0 AND TransactionDate <= DATEADD("dd", -90, GETDATE())
GROUP BY TransactionCode, TenantID

如何通过一个查询获取所有这些内容？

Answer 1

它可以这样做:

SELECT TransactionCode, TenantID, 
SUM(CASE WHEN Amount > 0 then Amount ELSE 0 END) AS Paid,
SUM(CASE WHEN Amount < 0 AND TransactionDate > DATEADD("dd", -30, GETDATE()) THEN Amount ELSE 0 END) AS ChargedCurrent,  
SUM(CASE WHEN Amount < 0 AND TransactionDate > DATEADD("dd", -60, GETDATE()) AND TransactionDate <= DATEADD("dd", -30, GETDATE()) THEN Amount ELSE 0 END) AS ChargedOver30
SUM(CASE WHEN Amount < 0 AND TransactionDate > DATEADD("dd", -90, GETDATE()) AND TransactionDate <= DATEADD("dd", -60, GETDATE()) then Amount Else 0 END) AS ChargedOver60,
SUM(CASE WHEN Amount < 0 AND TransactionDate <= DATEADD("dd", -90, GETDATE()) THEN Amount ELSE 0 END) AS ChargedOver90 
FROM tblTransaction
GROUP BY TransactionCode, TenantID