Entity Framework 6 Code First Trigger

Question

I'm using Entity Framework 6 Code First, and would like to create a Trigger.

How do I do this?

The reason I need the trigger is because a user may either edit the database directly or through a program I'm writing, and I need to make sure 2 columns in a table are not both null, and are not both not null.

I've been looking and can't find a way.

Is there any way to specify a trigger using code first?

Answer 1

Entity Framework has no support for triggers, although you can certainly manually execute a statement that would create a trigger, but you would need to do this after the table was created (if using migrations).

You can use the technique specified by Ladislav in EF 4.1 code-first adding a trigger to a table

Take note of his warning, however, EF will not be aware of any changes made in the trigger. If your intent is merely to ensure that 2 columns in a table are not null, you'd be better served with a constraint (constraints are also not supported by EF, but you can add them manually).

Answer 2

Check out my library EntityFramework.Triggers . It works at the Entity Framework layer, so the trigger events won't fire if someone modifies the database directly. The NuGet link is https://www.nuget.org/packages/EntityFramework.Triggers/

Answer 3

After you add a migration, open the migration file and create your trigger as shown below

Note: you need to run update-database to see the changes in your database.