EF 5-模型首次数据库迁移：发布到远程生产服务器后要更改模型？

Question

I'm developing in MVC 5, EF 5.0 code first. I publish the project using file sharing folder.

I can use database migration to update the developing localDb when the model is changed. However, after I published the project to a remote server, it shows the error of models being changed and migration required on the production web server which use a full SQL database server.

I know I can delete the database on the production server and let it recreates the database. However, there are already user entered data in the tables.

Is there a way to apply the model/database changes without recreate the database?

Answer 1

Yes there is a way. Actually there are several.

• You can generate a SQL script that can be applied to the production database. Run the Update-Database in the Package Manager Console with the -Script flag like so:

  Update-Database -Script -SourceMigration: InitialMigration -TargetMigration: LatestMigration

  Or use a tool like Red Gate SQL Compare to generate the script.

• On Application startup you can automatically upgrade the database by registering the MigrateDatabaseToLatestVersion database initializer:

  Database.SetInitializer(new MigrateDatabaseToLatestVersion());

You can read more about both methods in the article MSDN - Code First Migrations .

Answer 2

I never had the option to delete the database on the production. EF code first is not for that purpose, it's for development only,

There are a couple of options, if you use Visual Studio Ultimate, there is a schema compare tool under SQL Menu. Alternatively, you can use Red Gate SQL Compare tools.