查看查询而不选择T-SQL

Question

所以我试图构建一个视图查询，但我一直只使用联接失败，所以我最终导致了这种变形。。关于如何编写这个查询以便不必使用6个子选项，有什么建议吗？FeeSum和PaymentSum可以为null，所以理想情况下，我不希望结果集中出现这些值，而且我也不希望FeeSum与PaymentSum相等的结果。

快速提示：客户端是存储客户端信息(名称、地址等(的表customer在客户端上有一个fk，并且是客户端的shell表，payment是客户进行的所有付款的列表，订单是客户完成的所有订单的列表。

目标是获得一个列表，我们可以根据订单跟踪哪个客户需要支付开放费用。这是一个遗留项目，所以不要问为什么人们可以在付款前订购：(

SELECT 
cu.Id as [CustomerId]
, CASE
WHEN cl.IsPerson = 1
THEN cl.[AdditionalName] + ' ' + cl.[Name]
ELSE cl.AdditionalName
END as [Name]
, cl.CustomerNumber
, (SELECT SUM(o.Fee) FROM [publication].[Order] o WHERE o.[State] = 2 AND o.CustomerId = cu.Id) as [FeeSum]
, (SELECT SUM(p.Amount) FROM [publication].[Payment] p WHERE p.CustomerId = cu.Id) as [PaymentSum]
, (SELECT MAX(o.OrderDate) FROM [publication].[Order] o WHERE o.[State] = 2 AND o.CustomerId = cu.Id) as [LastOrderDate]
, (SELECT MAX(p.PaymentDate) FROM [publication].[Payment] p WHERE p.CustomerId = cu.Id) as [LastPaymentDate]
, (SELECT MAX(f.Created) FROM [client].[File] f WHERE f.TemplateName = 'Reminder' AND f.ClientId = cl.Id) as [LastReminderDate]
, (SELECT MAX(f.Created) FROM [client].[File] f WHERE f.TemplateName = 'Warning' AND f.ClientId = cl.Id) as [LastWarningDate]
FROM 
[publication].[Customer] cu
JOIN
[client].[Client] cl
ON cl.Id = cu.ClientId
WHERE
cu.[Type] = 0

提前谢谢，我希望我没有做错什么。

问候

Answer 1

您可以重写相关的子查询，转而使用联接：

SELECT
cu.Id AS [CustomerId],
CASE WHEN cl.IsPerson = 1
THEN cl.[AdditionalName] + ' ' + cl.[Name]
ELSE cl.AdditionalName END AS [Name],
cl.CustomerNumber,
o.FeeSum,
p.PaymentSum,
o.LastOrderDate,
p.LastPaymentDate,
f.LastReminderDate,
f.LastWarningDate
FROM [publication].[Customer] cu
INNER JOIN [client].[Client] cl
ON cl.Id = cu.ClientId
INNER JOIN
(
SELECT CustomerId, SUM(Fee) AS [FeeSum], MAX(OrderDate) AS [LastOrderDate]
FROM [publication].[Order]
WHERE o.[State] = 2
GROUP BY CustomerId
) o
ON o.CustomerId = cu.Id
INNER JOIN
(
SELECT CustomerId, SUM(Amount) AS [PaymentSum], MAX(PaymentDate) AS [LastPaymentDate]
FROM [publication].[Payment]
WHERE o.[State] = 2
GROUP BY CustomerId
) p
ON p.CustomerId = cu.Id
INNER JOIN
(
SELECT ClientId,
MAX(CASE WHEN TemplateName = 'Reminder' THEN Created END) AS [LastReminderDate],
MAX(CASE WHEN TemplateName = 'Warning'  THEN Created END) AS [LastWarningDate]
FROM [client].[File]
GROUP BY ClientId
) f
ON f.ClientId = cl.Id
WHERE
cu.[Type] = 0;