How do you seed data with Entity Framework Database First approach?

Question

I see many examples of seeding with Code First, but I'm not sure I understand what the idiomatic way of seeding the database when using EF Database First.

Database First is when you already have the database and you would like to use it for creating your model. In this scenario you most likely have the data in the database. You also don't want/can't drop the database. I wonder what is the scenario where you want to seed the database if you already have data. Anyways - you can add data using a sql script or just by creating a context, creating entities adding them to context and saving changes. Since you don't delete the database you probably want to do this only once. — Pawel
– Pawel, Commented May 11, 2013 at 4:55
In db first database creation/seeding can be done in any way you like. EF is a complete outsider there. — Gert Arnold
– Gert Arnold, Commented May 11, 2013 at 10:16

phil soady · Accepted Answer · 2013-05-11 05:08:46Z

1

Best practice is very situation dependent. Then there is the DEV versus PROD environments. Auto seed when using Drop and recreate on model change during DEV so you have test data makes the most sense. This is when it used most.

Of cause you can a have a test method that you trigger manually. I personally find the idea an automatically triggered seed method not that exciting and more for DEV prototyping when the DB structure is volatile. When using migrations, you tend to keep your hard earned test data. Some use Seeding during initial installation in PROD. Others will have a specific load routines triggered during the installation/commissioning process. I like to use custom load routines instead.

EDIT: A CODE FIRST SAMPLE. With DB First you just write to the Db normally.

// select the appropriate initializer for your situation eg
Database.SetInitializer(new MigrateDatabaseToLatestVersion<MyDbContext, MyMigrationConfiguration>());
Context.Database.Initialize(true);  // yes now please
//...
 public class MyMigrationConfiguration<TContext> : DbMigrationsConfiguration<TContext> 
    where TContext  : DbContext{

    public  MyMigrationConfiguration() {
        AutomaticMigrationsEnabled = true;  //fyi  options
        AutomaticMigrationDataLossAllowed = true; //fyi options
   }
    public override void Seed(TContext context)
    {
        base.Seed(context);
// SEED AWAY..... you have the context
    }

}

edited May 11, 2013 at 5:08

answered May 11, 2013 at 4:04

phil soady

11.4k5 gold badges55 silver badges100 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Pawel Over a year ago

this does not seem like database first. DB First does not support migrations in the first place.

phil soady Over a year ago

no its code first. Sorry. The Seed process goes with Code first. In DB first, the modeling process has as STOP here line of code to prevent the process launching. Im curious now about DB first and seeding. Clearly an Empty DB then. So the original comment is still valid. Just the sample is irrelevant since its DB first

Collectives™ on Stack Overflow

How do you seed data with Entity Framework Database First approach?

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related