Linq to sql LinqToSql对数据库生成不正确的查询

我对LinqToSql和PredicateBuilder有问题

我有下面的代码

Dim vQuery As IQueryable(Of Table1) = pContext.Table1
Dim predicate As Expression(Of System.Func(Of Table1, Boolean)) = Nothing

....

Dim predicateAdd As Expression(Of System.Func(Of Table1, Boolean)) = PredicateBuilder.True(Of Table1)()

predicateAdd = predicateAdd.And(Function(a As Table1) a.Table2.Table3.Select(Function(c) c.Column1).Contains(TextToSearch))

predicate = predicate.And(predicateAdd)

....

Me.Grid.DataSource = vQuery.Where(predicate)

这将生成对数据库的以下查询

SELECT [t0].[ID], ...
FROM [dbo].[Table1] AS [t0]
WHERE EXISTS(
    SELECT NULL AS [EMPTY]
    FROM [dbo].[Table2] AS [t1], [dbo].[Table3] AS [t2]
    WHERE ([t2].[Column1] = @p0) AND ([t1].[ID] = [t0].[ID]) AND ([t2].[ID] = [t1].[ID])
    )   
-- @p0 is TextToSearch

WHERE ([t2].[Column1] Like @p0)

但那不是我想要的

这行代码

a.Table2.Table3.Select(Function(c) c.Column1).Contains(TextToSearch)

必须生成对数据库的下一个查询

SELECT [t0].[ID], ...
FROM [dbo].[Table1] AS [t0]
WHERE EXISTS(
    SELECT NULL AS [EMPTY]
    FROM [dbo].[Table2] AS [t1], [dbo].[Table3] AS [t2]
    WHERE ([t2].[Column1] = @p0) AND ([t1].[ID] = [t0].[ID]) AND ([t2].[ID] = [t1].[ID])
    )   
-- @p0 is TextToSearch

WHERE ([t2].[Column1] Like @p0)

但不是这个

WHERE ([t2].[Column1] = @p0)

---

如果我在某个地方出错，或者这是LinqToSql中的一个错误，那么在调用Select（）的结果上调用Contains与在字符串字段上调用它不同。生成的代码完全符合您所编写的内容

由于您以这种方式调用了Contains（），因此它正在测试返回集合中的每个项是否相等