Code First Migrations: Beta 1 Released
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Visit msdn.com/data/ef for the latest information on current and past releases of EF.
For Code First Migrations see http://msdn.com/data/jj591621
At the end of September we released Alpha 3 of Code First Migrations. Based on Alpha 2 and Alpha 3 feedback your telling us that we are building the right thing… so it’s time to start improving quality and working towards our first go-live release. Today we are making Beta 1 available which is our first step in that direction.
This release has been primarily about improving quality and cleaning up the API surface ready to RTM. There aren’t any significant changes to the user experience.
Some more notable changes include:
- Class and method renames. We’ve done a lot of renaming and refactoring since Alpha 3. There are some important notes in the next section about how these changes affect migrations that were generated with Alpha 3.
- Migrations will now create indexes on foreign key columns.
- Improved model change detection. We fixed a number of bugs in the way we look for changes in your model and scaffold migrations. This includes things such as detecting CascadeDelete changes on relationships.
Upgrading From Alpha 3
If you have Alpha 3 installed you can use the ‘Update-Package EntityFramework.Migrations’ command in Package Manager Console to upgrade to Beta 1. You will need to close and re-open Visual Studio after updating, this is required to reload the updated command assemblies.
You will also need to update any existing code to reflect a series of class and method renames:
- The Settings class has been renamed to Configuration. When you update the NuGet package you will get a new Configuration.cs (or Configuration.vb) file added to your project. You will need to remove the old Settings file. If you added any logic for seed data etc. you will need to copy this over to the new Configuration class before removing Settings.
(This file rename is a result of us changing the base class for this class from DbMigrationContext to DbMigrationsConfiguration)
- If you have existing migrations that call ChangeColumn you will need to update them to call AlterColumn instead.
- There is a designer code file associated with each migration in your project, for migrations generated with Alpha 3 you will need to edit this file. You will need to add a using statement for System.Data.Entity.Migrations.Infrastructure and change the references to IDbMigrationMetadata to IMigrationMetadata.
RTM as EF4.3
So far we have been shipping Migrations as a separate EntityFramework.Migrations NuGet package that adds on to the EntityFramework package. As our team has been looking at the grow-up story to Migrations from a Code First database that was created by just running a Code First application it’s becoming clear that Migrations is a very integral part of Code First. We’ve also heard feedback that we need to reduce the number of separate components that make up EF. Because of this we are planning to roll the migrations work into the EntityFramework NuGet package so that you get everything you need for Code First applications in a single package. This will be the EF4.3 release.
The timeline to our first RTM of Code First Migrations depends on the feedback we get on this release but we are currently aiming to have a go-live release available in early 2012. We’re planning to make a Release Candidate available before we publish the final RTM.
What’s Still Coming
Beta 1 only includes the Visual Studio integrated experience for Code First Migrations. We also plan to deliver a command line tool and an MSDeploy provider for running Code First Migrations.
We are planning to include the command line tool as part of the upcoming RTM.
We’re working with the MSDeploy team to get some changes into the next release of MSDeploy to support our new provider. Our MSDeploy provider will be available when the next version of MSDeploy is published. This will be after our initial RTM of Code First Migrations.
There are two walkthroughs for Beta 1. One focuses on the no-magic workflow that uses a code-based migration for every change. The other looks at using automatic migrations to avoid having lots of code in you project for simple changes.
- Code First Migrations: Beta 1 ‘No-Magic’ Walkthrough
- Code First Migrations: Beta 1 ‘With-Magic’ Walkthrough (Automatic Migrations)
This is a preview of features that will be available in future releases and is designed to allow you to provide feedback on the design of these features. It is not intended or licensed for use in production. If you need assistance we have an Entity Framework Pre-Release Forum.
ADO.NET Entity Framework Team