如何在EF LINQ中联接表

本文介绍了如何在EF LINQ中联接表的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

当我尝试联接表时

var query = from foo in db.Foos from bar in db.Bars where foo.ID == bar.FooID where foo.ID == 45 select bar; query.toArray()

我收到这样的错误

Unable to create a constant value of type 'Bar'. Only primitive types ('such as Int32, String, and Guid') are supported in this context.

推荐答案

试试看:

var query = from foo in db.Foos join bar in db.Bars on foo.ID equals bar.FooID where foo.ID == 45 select bar;

无论如何，我建议您在EDM设计器中对Foo和Bar之间的关系进行建模，这样就无需显式联接:

Anyway, I suggest you model the relation between Foo and Bar in the EDM designer, this way you don't need an explicit join:

var query = from foo in db.Foos where foo.ID == 45 from bar in foo.Bars select bar;