Not in 的LinQ实现

 

I'm having a problem with coding a LINQ to SQL query. In TSQL, I would use the following:

 

SELECT BarrierTypeKey, Description

FROM dbo.BarrierTypes WHERE BarrierTypeKey NOT IN (

SELECT DISTINCT BarrierTypeKey FROM Barriers WHERE WorksheetKey = @WorksheetKey

)

ORDER BY Description

 

For this I have the following LINQ statement

 

Dim query = From t In dc.BarrierTypes Where Not (From b In dc.Barriers Where b.WorksheetKey = worksheetKey Select b.BarrierTypeKey).Contains(t.BarrierTypeKey) Select t Order By Description

When it runs, I get the message:

 

Method 'System.Object CompareObjectEqual(System.Object, System.Object, Boolean)' has no supported translation to SQL.

Not sure where to go next.