实体框架-查询可为空的列的问题

Question

I have a problem querying data from a table with a nullable tinyint column.
The problem seems to be that the query is generated as:

AND ( CAST( [Extent1].[PositionEffect] AS int) = @p__linq__3)

=> @p__linq__3 = NULL

If i run that query manually it doesn't turn up any results. However, when I replace the query with:

AND ([Extent1].[PositionEffect] IS @p__linq__3)

it turns up the expected results.
My C# query looks like this:

 context.Allocations.Where(x => ... && x.PositionEffect == (byte?) positionEffect)

So, why is the entity framework generating the incorrect query here and is there any way to fix this?

Thanks,

Tom

Answer 1

正如Will A指出的那样，这似乎是Entity Framework中的一个已报告错误，并且生成正确查询的解决方法是：

 (positionEffect == null ? x.PositionEffect == null : x.PositionEffect == (byte?)positionEffect)