Entity Framework 6 CodeFirst/DatabaseFirst migration data preservation? - entity-framework

Question

I am new to the ADO .NET technologies. I know EF6 is built on top of ADO .NET. I checked out some of Microsoft's Data technologies reference site (http://msdn.microsoft.com/en-us/data/).
I am trying to figure out if a CodeFirst created database that is modified after initial creation can be modified and migrated without loss of data. One of the tutorial videos on their site says DatabaseFirst EF mappings created with the entity designer cannot be migrated without loss of data after a change is made to the schema.
Do migrations for changes to schemas based on CodeFirst designs also suffer from that problem of data loss after migration?

Answer 1

This is good article you should read:
http://www.asp.net/mvc/overview/getting-started/getting-started-with-ef-using-mvc/migrations-and-deployment-with-the-entity-framework-in-an-asp-net-mvc-application
In the deployment section you saw the MigrateDatabaseToLatestVersion
initializer being used. Code First also provides other initializers,
including CreateDatabaseIfNotExists (the default),
DropCreateDatabaseIfModelChanges (which you used earlier) and
DropCreateDatabaseAlways. The DropCreateAlways initializer can be
useful for setting up conditions for unit tests. You can also write
your own initializers, and you can call an initializer explicitly if
you don't want to wait until the application reads from or writes to
the database. At the time this tutorial is being written in November,
2013, you can only use the Create and DropCreate initializers before
you enable migrations. The Entity Framework team is working on making
these initializers usable with migrations as well.
For more information about initializers, see Understanding Database
Initializers in Entity Framework Code First and chapter 6 of the book
Programming Entity Framework: Code First by Julie Lerman and Rowan
Miller.
quoted from that article.