Using Entity Framework (code first) migrations in production

.net entity-framework ef-code-first entity-framework-migrations
devdigital picture devdigital · Jun 1, 2012 · Viewed 47.8k times · Source

I'm just looking into using EF migrations for our project, and in particular for performing schema changes in production between releases.

I have seen mentioned that there is an API to perform these migrations at run-time using the DbMigration class, but I can't find any specific examples.

Ideally, I would want one DbMigration file for every database change, and for those changes to be applied automatically on application start up from the current version up to the latest version.

Answer

WDRust picture WDRust · Jun 1, 2012

There is a Database Initializer you can use to achieve the migration to latest version on startup (or better, the dbinitializer will kick in on first db access), the MigrateDatabaseToLatestVersion, you use it like that:

Database.SetInitializer<ObjectContext>(
    new MigrateDatabaseToLatestVersion<ObjectContext, Configuration>());

Regarding having one file per migration, if you enable automatic migrations you will find them in the Migrations folder (by default) in the root of your project.

Relevant info, with examples, here: http://weblogs.asp.net/fredriknormen/archive/2012/02/15/using-entity-framework-4-3-database-migration-for-any-project.aspx

Related questions

Introducing FOREIGN KEY constraint may cause cycles or multiple cascade paths - why?

I've been wrestling with this for a while and can't quite figure out what's happening. I have a Card entity which contains Sides (usually 2) - and both Cards and Sides have a Stage. I'm using EF Codefirst migrations and the …

Read More
Ignoring a class property in Entity Framework 4.1 Code First

My understanding is that the [NotMapped] attribute is not available until EF 5 which is currently in CTP so we cannot use it in production. How can I mark properties in EF 4.1 to be ignored? UPDATE: I noticed something else strange. …

Read More
How to fix the datetime2 out-of-range conversion error using DbContext and SetInitializer?

I'm using the DbContext and Code First APIs introduced with Entity Framework 4.1. The data model uses basic data types such as string and DateTime. The only data annotation I'm using in some cases is [Required], but that's not on any …

Read More