Question

出于某种原因，我在下面的代码中遇到语法错误。我想要实现的是带有多个连接条件的LEFT JOIN。语法错误发生在关键字INTO foobar中。 VS 2012表示意外的令牌。任何帮助都会很棒，谢谢！

 Dim results = From f In foo _
                   Join b In bar On new with {f.Type,f.ID} Equals New With {"Test",b.ID} into fooBar _
                   from x in foobar.DefaultEmpty() _ 
                   Where foo.id = 1

Answer 1

您需要Group Join：

Dim results = From f In foo _
               Group Join b In bar On 
                   New With {f.Type,f.ID} Equals New With {"Test",b.ID} _
                   Into fooBar = Group _
               from x in foobar.DefaultEmpty() _ 
               Where foo.id = 1

Answer 2

尝试投射f.ID或b.ID

 Dim results = From f In foo _
                   Join b In bar On new with {f.Type, CInt(f.ID)} Equals New With {"Test", CInt(b.ID)} into fooBar _
                   from x in foobar.DefaultEmpty() _ 
                   Where foo.id = 1

Linq To Sql使用多个join子句离开了join

2 个答案: