根据详细信息过滤器返回主行

发布于 2024-08-18 16:24:02 字数 658 浏览 2 评论 0原文

我有一个查询，我想根据详细信息是否满足特定条件返回主行。

例如，如果至少一个详细信息行具有 SomeProperty = X，我只想返回特定的主行。

基于以下谓词：

        predicate = predicate.And(p =>
                                  p.BasketItems.Where(obi => obi.BasketItemTypeID ==
                                                                  (int) BasketType.Refund).Count() > 0);

生成以下 SQL：

SELECT COUNT(*)
    FROM [dbo].[BasketItems] AS [t3]
    WHERE ([t3].[BasketId] = [t0].[OrderBasketID]) AND ([t3].[BasketItemTypeID] = 3)
    )) > 0)

问题是它正在执行表扫描，因此查询需要跑一会儿。

只是检查我没有做任何疯狂的事情，并想知道是否有什么可以加快这个查询的速度？

谢谢邓肯

原文

I have a query where I want to return Master rows based on whether the detail fulfil a certain criteria.

For example, I only want to return a particular Master row if AT LEAST one of the Detail rows have SomeProperty = X.

Based on the following predicate:

        predicate = predicate.And(p =>
                                  p.BasketItems.Where(obi => obi.BasketItemTypeID ==
                                                                  (int) BasketType.Refund).Count() > 0);

generates the following SQL:

SELECT COUNT(*)
    FROM [dbo].[BasketItems] AS [t3]
    WHERE ([t3].[BasketId] = [t0].[OrderBasketID]) AND ([t3].[BasketItemTypeID] = 3)
    )) > 0)

Problem with this is it's doing a table scan, so the query takes a while to run.

Just checking that I'm not doing anything crazy and wonder if there's anything that can speed up this query?

Thanks
Duncan

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千年*琉璃梦 2024-08-25 16:24:02

select M.basketID, max(M.field1) as field1, max(M.field2) as field2 
from dbo.basketItems as M
Inner join detail on M.basketID = detail.basketID
where detail.basketItemTypeID = '3'
group by M.basketID

（将主表连接到详细信息。选择详细信息具有所需条件的所有行。将结果行压缩到每个主记录 1 行。）

select M.basketID, max(M.field1) as field1, max(M.field2) as field2 
from dbo.basketItems as M
Inner join detail on M.basketID = detail.basketID
where detail.basketItemTypeID = '3'
group by M.basketID

(Join master to detail. select all rows where detail has the required criterion. Squish the resulting rows down to 1 per master record.)

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