How to change a clustered index in Entity Framework 6.1 Code First model and apply it to an Azure database

Question

Using the Entity Framework 6.1 code first model, what is the best way to go about changing the clustered index on a table from the default ID to another set of columns. Azur

Answer 1

After the migration file is created, modify the generated code, disabling the clustered index for the primary key by setting the clustered property to false.

Being that Azure does not allow a table without a clustered index, and there is no utility in SQL Server to 'change' a clustered index on a table, it is necessary create a new table with the clustered index and migrate the existing data to it. The code below renames the original table, migrates the data to the new table that was created with the new clustered index and drops the original table.

        RenameTable("dbo.UserProfiles", "UserProfiles_PreMigrate");

        CreateTable(
            "dbo.UserProfiles",
            c => new
            {
                Id = c.Guid(nullable: false),
                UserID = c.Guid(nullable: false),
                FieldID = c.Guid(nullable: false),
                Value = c.String(nullable: false, maxLength: 400),
            })
            .PrimaryKey(t => t.Id, clustered: false)
            .Index(t => t.UserID, clustered: true, name: "CI_UserProfiles_UserID");

        Sql(@"
            INSERT [dbo].[UserProfiles]
            (ID,
             UserID,
             FieldID,
             Value)
            SELECT
             ID,
             UserID,
             FieldID,
             Value
            FROM dbo.UserProfiles_PreMigrate

        ");

        DropTable("UserProfiles_PreMigrate");

Any existing table constraints will be lost in this operation, so it will be necessary to recreate and indexes,foreign keys, etc on the table.