拿着这个:
int? item1 = null;
int? item2 = null;
someObjectList.Where(x => x.SomeItem1 == (item1 ?? x.SomeItem1)
&& x.SomeItem2 == (item2 ?? x.SomeItem2)
);
wheresomeObjectList
不为空,SomeItem1
并且在列表SomeItem2
中null
的所有对象中。
为什么什么都不返回?
编辑:
我的代码:
public void GetPlacementsByMaterial(long clientMaterialID)
{
ClientMaterial clientMaterial = ((ApplicationEntityModel)NavigationItem.ObjectContext).ClientMaterial.FirstOrDefault(x => x.ClientMaterialID == clientMaterialID);
var list = GetPlacementList(supplier, mediaSpace);
PlacementsList = list.Where(x => x.MediaCategoryFormatID == (clientMaterial.MediaCategoryFormatID ?? x.MediaCategoryFormatID)
&& x.MediaCategorySizeID == (clientMaterial.MediaCategorySizeID ?? x.MediaCategorySizeID)
);
}
所有的 ID 都是Nullable<long>
.
编辑:
SQL 探查器:
SELECT *
FROM [dbo].[CampaignSchedulePlacements] AS [Extent5]
WHERE ([Extent5].[MediaCategoryFormatID] = [Extent5].[MediaCategoryFormatID]) AND ([Extent5].[MediaCategorySizeID] = [Extent5].[MediaCategorySizeID])
注意:清理了`SQL.