How to rename a database column in Entity Framework 5 Code First migrations without losing data?

Question

I got the default ASP.NET MVC 4 template successfully running with EF 5.0 Code First Migrations. However, when I update a model property name, the corresponding table column data is dropped by EF 5.0.

Is it somehow possible to rename the table column without dropping data in an automated way?

Answer 1

Manually edit the Up and Down methods of the migration to use the RenameColumn method to replace the AddColumn and DropColumn that it automatically generates for you.

Answer 2

As already said, replace the AddColumn and DropColumn that is automatically generated with RenameColumn.

Example:

namespace MyProject.Model.Migrations {     using System;     using System.Data.Entity.Migrations;      public partial class RenameMyColumn : DbMigration     {         public override void Up()         {             // Remove the following auto-generated lines             AddColumn("dbo.MyTable", "NewColumn", c => c.String(nullable: false, maxLength: 50));             DropColumn("dbo.MyTable", "OldColumn");              // Add this line             RenameColumn("dbo.MyTable", "OldColumn", "NewColumn");         }          public override void Down()         {             // Remove the following auto-generated lines             AddColumn("dbo.MyTable", "OldColumn", c => c.String(nullable: false, maxLength: 50));             DropColumn("dbo.MyTable", "NewColumn");              // Add this line             RenameColumn("dbo.MyTable", "NewColumn", "OldColumn");         }     } }