实体框架中多列的唯一键约束 [英] Unique Key constraints for multiple columns in Entity Framework
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问题描述
我使用的是实体框架 5.0 代码优先;
I'm using Entity Framework 5.0 Code First;
public class Entity
{
[Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public string EntityId { get; set;}
public int FirstColumn { get; set;}
public int SecondColumn { get; set;}
}
我想让 FirstColumn
和 SecondColumn
之间的组合是唯一的.
I want to make the combination between FirstColumn
and SecondColumn
as unique.
示例:
Id FirstColumn SecondColumn
1 1 1 = OK
2 2 1 = OK
3 3 3 = OK
5 3 1 = THIS OK
4 3 3 = GRRRRR! HERE ERROR
有没有办法做到这一点?
Is there anyway to do that?
推荐答案
使用 Entity Framework 6.1,您现在可以执行以下操作:
With Entity Framework 6.1, you can now do this:
[Index("IX_FirstAndSecond", 1, IsUnique = true)]
public int FirstColumn { get; set; }
[Index("IX_FirstAndSecond", 2, IsUnique = true)]
public int SecondColumn { get; set; }
属性中的第二个参数用于指定索引中列的顺序.
更多信息:MSDN
The second parameter in the attribute is where you can specify the order of the columns in the index.
More information: MSDN
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