如何在实体框架中映射关系

I have 3 tables

我有3张桌子

=================    =================    =================
| TableA        |    | RelationAC    |    | TableC        |
=================    =================    =================
| IdA           |    | Id            |    | IdC           |
|               |    | IdA           |    |               |
| Field1A       |    | IdC           |    | Field1C       |
=================    =================    =================
=================