[英]Entity Framework - How do I join tables on non-primary key columns in secondary tables?
I want to join 2 tables using entity framework. 我想使用实体框架加入2个表。 I want the join to the second table to be on a non-primary key column.
我希望第二个表的连接位于非主键列上。
eg I have a table Foo with fields 例如,我有一个带有字段的表Foo
Foo.Id (PK)
Foo.DbValue
and table Bar 和桌子吧
Bar.Id (PK)
Bar.DbValue
Bar.Description
And I want to join Foo to Bar in EF on the DbValue field. 我想在DbValue领域加入Foo到EF吧。
In hibernate/nhibernate one can do this by adding a column parameter to a many-to-one. 在hibernate / nhibernate中,可以通过向多对一添加列参数来实现。 roughly like this
大致是这样的
<class name="Foo" table="Foo>
<id name="Id" column="Id" />
<many-to-one name="Bar" class="Bar" column="**DbValue**" />
</class>
Thanks in advance if anyone knows how to do this in EF. 如果有人知道如何在EF中这样做,请提前感谢。
Well you can't do this as a named relationship (ie the standard way). 那么你不能把它作为命名关系(即标准方式)。
So this means the relationship is NOT part of the model. 所以这意味着这种关系不是模型的一部分。
However you can still do a standard LINQ join though: 但是,您仍然可以执行标准的LINQ连接:
from f in ctx.Foo
join b in ctx.Bar on f.DbValue equals b.DbValue
select new {f,b}
Hope this helps 希望这可以帮助
Check out my EF Tips series. 看看我的EF Tips系列。
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