CODEWITHSUNDEEP
c#.netentity-frameworkentity-framework-4
Justin Helgerson
Justin Helgerson

Reputation: 25521

Stop Entity Framework from modifying database

I'm starting to play around with the code-first approach to the entity framework, primarily so that I can decorate my properties with annotations for display in my view (otherwise, right now I have to create a class that is nearly identical to the one that entity framework generated for me just so I can add annotations, and then copy the data from one object to the next).

Right now it looks like when I start my application it is trying to create a database.

I do not want entity framework to ever modify my database. No. Not ever. Don't even try it. It really isn't that hard to modify databases; I would feel much more comfortable if I did that myself. I don't need a framework to hold my hand when designing a database.

Can I tell the framework to stop trying to modify my database? I'm very hesitant to use code-first now as the fact that it's trying to modify my database is rather frightening. Even in development I never want to see it happen.

Am I out of luck?

Upvotes: 43

Views: 20414

Answers (5)

BillB4
BillB4

Reputation: 29

I realize this thread is old but hopefully the OP found the answer. If not...

Have Visual Studio generate the EF6 entity classes from the existing database:

https://www.entityframeworktutorial.net/code-first/code-first-from-existing-database.aspx

and then add (as already said):

Database.SetInitializer<SchoolDBContext>(null);

to stop EF6 from messing with the database.

Note that a potential issue with the auto-generated classes is the resultant code uses fluent.

Upvotes: -1

jrummell
jrummell

Reputation: 43067

If you don't want EF to create your database, you can disable the database initializer:

public class SchoolDBContext: DbContext 
{
    public SchoolDBContext() : base("SchoolDBConnectionString")
    {            
        //Disable initializer
        Database.SetInitializer<SchoolDBContext>(null);
    }
    public DbSet<Student> Students { get; set; }
    public DbSet<Standard> Standards { get; set; }
}

See http://www.entityframeworktutorial.net/code-first/turn-off-database-initialization-in-code-first.aspx

Upvotes: 66

sclarson
sclarson

Reputation: 4422

If you want to use EF but never modify the database then you probably don't want code first. You probably want something more like database first.

http://blogs.msdn.com/b/adonet/archive/2011/03/15/ef-4-1-model-amp-database-first-walkthrough.aspx

Links from answer comments:
http://automapper.codeplex.com/
Getting Started with AutoMapper

edit: I misunderstood the goal, you should reference this answer where the following correct code was given:

If you don't want EF to create your database, you can disable the database initializer

Database.SetInitializer<MyContext>(null);

Upvotes: 4

Lloyd Powell
Lloyd Powell

Reputation: 18760

When you declare you're initialiser, use the base class:

public class DatabaseInitialiser : CreateDatabaseIfNotExists<MyContext>

rather than :

public class DatabaseInitialiser : RecreateDatabaseIfModelChanges<MyContext>

Or if you use : 

Database.SetInitializer<MyContext>(new RecreateDatabaseIfModelChanges<MyContext>);

replace this with :

Database.SetInitializer<MyContext>(new CreateDatabaseIfNotExists<MyContext>);

Upvotes: 2

CodeCaster
CodeCaster

Reputation: 151588

Since code first pretty much exactly does what you describe, I do not understand your question.

If you don't want EF to fiddle with your database, then generate a model from your existing database.

Upvotes: 1

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