实体框架会删除未创建的表吗？

Question

I have an existing database. It has tables that were created manually (in SQL, not with EF). I have to add EF Code First Migrations, for reasons.

When Update-Database is run on an environment that hasn't had its migrations applied yet, I want EF to create the tables, but I DON'T want it to drop the whole database. Is that what it will do, and if so how can I stop it?

In my database context I'm not sure whether to use

//Disable initializer
Database.SetInitializer<ApplicationDbContext>(null);

or to use

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

According to the documentation it looks like CreateDatabaseIfNotExists will actually still drop the database if the EF tables don't exist.

But if I just disable the initializer then I think that means it won't even create the EF tables. Neither of these solutions seem good.

Answer 1

If you have some tables in your db, that created manually, you can enable migration with following commands:

PM>Enable-Migrations
PM>AddMigration [A_Name_For_Your_Migration] -IgnoreChanges
PM>Update-Databases