Question

我希望此查询将所有不同的网上商店日期插入到第二个表中，如果它们尚不存在于网上商店DataSet

以下查询似乎忽略了AND t1.[DataSet] = 'webshop'参数，并且未插入新的网上商店值，因为它们包含相同的日期范围，即。它们都包含01/02/2013

INSERT INTO [ImportedDateRange] ([DataSet],[DateRange]) 
select DISTINCT 'webshop', cast(T2.[OrderCreatedDate] as DATE) 
from webshop T2 
left join [ImportedDateRange] T1 
on cast(T2.[OrderCreatedDate] as DATE) = t1.[DateRange] 
where t1.[DateRange] is null
AND t1.[DataSet] = 'webshop'

理想的结果是，只有在网上商店尚不存在时才输入网上商店的日期范围（如果查询运行两次，这可以防止重复数据）

DataSet    DataRange
business   01/02/2013
business   02/02/2013
business   03/02/2013
webshop    01/02/2013
webshop    02/02/2013
webshop    03/02/2013

Answer 1

您应该将t1.[DataSet] = 'webshop'条件从WHERE类

移到JOIN

INSERT INTO [ImportedDateRange] ([DataSet],[DateRange]) 
select DISTINCT 'webshop', cast(T2.[OrderCreatedDate] as DATE) 
from webshop T2 
left join [ImportedDateRange] T1 
on cast(T2.[OrderCreatedDate] as DATE) = t1.[DateRange] 
         AND t1.[DataSet] = 'webshop'
where t1.[DateRange] is null

SQL INSERT值（如果它们尚不存在）

1 个答案: