关于vb.net:Query with left join in linq


Query with left join in linq

你好，我是想给在LINQ查询但我need some help…P＞＜／

我有两个表：langavailable and official translations我想，如果是在网上甚至还有不翻译记忆P＞＜／

例如：forP＞＜／

1
2
3
4
           LangId: 1  TranslationID:10  Translation: Hello
           LangId: 2  TranslationID:10  Translation: Bonjour
           LangId: 1  TranslationID:11  Translation: Thanks
           LangId: 2  TranslationID:11  Translation:

这是我给你：P＞＜／

1
2
3
4
 Dim query = From c In db.LangAvailable _
             Join o In db.Translate On c.ID_Lang Equals o.Lang_ID _
             Where o.TranslationID = 243 _
             Select New With {c.LangId, o.Translation}

只给我一本记录if there in the translation table翻译的不…任何想法如何，我可以得到吗？P＞＜／

thanxP＞＜／

你可以使用GroupJoin来完成你想做的事情。试试这个：

1
2
3
4
5
Dim query = From c In db.LangAvailable _
                Group Join o In db.Translate On c.ID_Lang Equals o.Lang_ID Into Group _
                From o In Group.DefaultIfEmpty() _
                Where o.TranslationId = 243 _
                Select LangId = c.ID_Lang, Translation = If(o.Translation Is Nothing, Nothing, o.Translation)