Is it possible to set a unique constraint using Entity Framework Code First?

asp.net-mvc entity-framework entity-framework-5 entity-framework-6
subi_speedrunner picture subi_speedrunner · Nov 10, 2014 · Viewed 45.1k times · Source

I want to enforce Unique constraint in a table & I am using Entity Framework Code-First.

Is it possible to add a unique constraint using EF 6 as i believe in earlier versions it was not possible.

Answer

SBirthare picture SBirthare · Nov 10, 2014

It appears that the unique constraint feature that was scheduled to release with Version 6 got pushed to 6.1.

With EF 6.1, you can define a constraint using the Index attribute as shown below:

[Index("IX_FirstAndSecond", 1, IsUnique = true)]
public int FirstColumn { get; set; }

[Index("IX_FirstAndSecond", 2, IsUnique = true)]
public int SecondColumn { get; set; }

OR

You can use Fluent API as shown here in MSDN

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