Question

以下查询有效，但是“o.opendate不为null且o.orderdate不为null且o.closedate为null且o.canceldate为null”where子句的部分只需要应用于orderID计数（定单计数）。现在它正在应用于整个结果集，这不是我想要的。如何更改查询以执行此操作？这些表也非常大，所以我非常依赖索引，并且出于性能原因不尽量使用subquerys。任何帮助将不胜感激

select s.ZipCode, count(o.[OrderID]) orderCount, b.Longitude, b.Latitude, b.ordering 
from ZipCodeServiceAvailability s  
left join pdx_orders_view o on s.ZipCode = left(o.[ZipCode], 5)  
left join ZipCodeBoundaries b on s.ZipCode = b.ZipCode  
Where s.state = 'TX' and Ordering % 10 = 0 and 
     o.opendate is not null and o.orderdate is not null and o.closedate is null and o.canceldate is null  
Group By s.ZipCode, IsServiced, b.Longitude, b.Latitude, b.Ordering  
Order by s.ZipCode, b.Ordering

Answer 1

您需要一个包含 SUM 的案例陈述：

select sum(case when o.opendate is not null and o.orderdate is not null and o.closedate is null and o.canceldate is null
             then 1 else 0
        end) as OrderCount

然后，您应该从where子句中删除条件。

Answer 2

你可以用having子句做你想做的事。

select s.ZipCode, count(o.[OrderID]) orderCount, b.Longitude, b.Latitude, b.ordering 
from ZipCodeServiceAvailability s  
left join pdx_orders_view o on s.ZipCode = left(o.[ZipCode], 5)  
left join ZipCodeBoundaries b on s.ZipCode = b.ZipCode  
Where s.state = 'TX' and Ordering % 10 = 0 and 
     o.opendate is not null 
Group By s.ZipCode, IsServiced, b.Longitude, b.Latitude, b.Ordering  
Having count(o.[OrderID]) is not null
Order by s.ZipCode, b.Ordering

在不使用子查询的情况下，添加要计数的where子句而不是整个查询

2 个答案: