Entity Framework Migrations renaming tables and columns

Question

I renamed a a couple entities and their navigation properties and generated a new Migration in EF 5. As is usual with renames in EF migrations, by default it was going to drop objects and recreate them. That isn't what I wanted so I pretty much had to build the migration file from scratch.

    public override void Up()
    {
        DropForeignKey("dbo.ReportSectionGroups", "Report_Id", "dbo.Reports");
        DropForeignKey("dbo.ReportSections", "Group_Id", "dbo.ReportSectionGroups");
        DropForeignKey("dbo.Editables", "Section_Id", "dbo.ReportSections");
        DropIndex("dbo.ReportSectionGroups", new[] { "Report_Id" });
        DropIndex("dbo.ReportSections", new[] { "Group_Id" });
        DropIndex("dbo.Editables", new[] { "Section_Id" });

        RenameTable("dbo.ReportSections", "dbo.ReportPages");
        RenameTable("dbo.ReportSectionGroups", "dbo.ReportSections");
        RenameColumn("dbo.ReportPages", "Group_Id", "Section_Id");

        AddForeignKey("dbo.ReportSections", "Report_Id", "dbo.Reports", "Id");
        AddForeignKey("dbo.ReportPages", "Section_Id", "dbo.ReportSections", "Id");
        AddForeignKey("dbo.Editables", "Page_Id", "dbo.ReportPages", "Id");
        CreateIndex("dbo.ReportSections", "Report_Id");
        CreateIndex("dbo.ReportPages", "Section_Id");
        CreateIndex("dbo.Editables", "Page_Id");
    }

    public override void Down()
    {
        DropIndex("dbo.Editables", "Page_Id");
        DropIndex("dbo.ReportPages", "Section_Id");
        DropIndex("dbo.ReportSections", "Report_Id");
        DropForeignKey("dbo.Editables", "Page_Id", "dbo.ReportPages");
        DropForeignKey("dbo.ReportPages", "Section_Id", "dbo.ReportSections");
        DropForeignKey("dbo.ReportSections", "Report_Id", "dbo.Reports");

        RenameColumn("dbo.ReportPages", "Section_Id", "Group_Id");
        RenameTable("dbo.ReportSections", "dbo.ReportSectionGroups");
        RenameTable("dbo.ReportPages", "dbo.ReportSections");

        CreateIndex("dbo.Editables", "Section_Id");
        CreateIndex("dbo.ReportSections", "Group_Id");
        CreateIndex("dbo.ReportSectionGroups", "Report_Id");
        AddForeignKey("dbo.Editables", "Section_Id", "dbo.ReportSections", "Id");
        AddForeignKey("dbo.ReportSections", "Group_Id", "dbo.ReportSectionGroups", "Id");
        AddForeignKey("dbo.ReportSectionGroups", "Report_Id", "dbo.Reports", "Id");
    }

All I'm trying to do is rename dbo.ReportSections to dbo.ReportPages and then dbo.ReportSectionGroups to dbo.ReportSections. Then I need to rename the foreign key column on dbo.ReportPages from Group_Id to Section_Id.

I am dropping the foreign keys and indexes linking the tables together, then I am renaming the tables and the foreign key column, then I'm adding the indexes and foreign keys again. I assumed this was going to work but I am getting a SQL error.

Msg 15248, Level 11, State 1, Procedure sp_rename, Line 215 Either the parameter @objname is ambiguous or the claimed @objtype (COLUMN) is wrong. Msg 4902, Level 16, State 1, Line 10 Cannot find the object "dbo.ReportSections" because it does not exist or you do not have permissions.

I'm not having an easy time figuring out what is wrong here. Any insight would be tremendously helpful.

Solution 1

Nevermind. I was making this way more complicated than it really needed to be.

This was all that I needed. The rename methods just generate a call to the sp_rename system stored procedure and I guess that took care of everything, including the foreign keys with the new column name.

public override void Up()
{
    RenameTable("ReportSections", "ReportPages");
    RenameTable("ReportSectionGroups", "ReportSections");
    RenameColumn("ReportPages", "Group_Id", "Section_Id");
}

public override void Down()
{
    RenameColumn("ReportPages", "Section_Id", "Group_Id");
    RenameTable("ReportSections", "ReportSectionGroups");
    RenameTable("ReportPages", "ReportSections");
}

Solution 2

If you don't like writing/changing the required code in the Migration class manually, you can follow a two-step approach which automatically make the RenameColumn code which is required:

Step One Use the ColumnAttribute to introduce the new column name and then add-migration (e.g. Add-Migration ColumnChanged)

public class ReportPages
{
    [Column("Section_Id")]                 //Section_Id
    public int Group_Id{get;set}
}

Step-Two change the property name and again apply to same migration (e.g. Add-Migration ColumnChanged -force) in the Package Manager Console

public class ReportPages
{
    [Column("Section_Id")]                 //Section_Id
    public int Section_Id{get;set}
}

If you look at the Migration class you can see the automatically code generated is RenameColumn.

Solution 3

In EF Core, I use the following statements to rename tables and columns:

As for renaming tables:

    protected override void Up(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.RenameTable(
            name: "OldTableName",
            schema: "dbo",
            newName: "NewTableName",
            newSchema: "dbo");
    }

    protected override void Down(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.RenameTable(
            name: "NewTableName",
            schema: "dbo",
            newName: "OldTableName",
            newSchema: "dbo");
    }

As for renaming columns:

    protected override void Up(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.RenameColumn(
            name: "OldColumnName",
            table: "TableName",
            newName: "NewColumnName",
            schema: "dbo");
    }

    protected override void Down(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.RenameColumn(
            name: "NewColumnName",
            table: "TableName",
            newName: "OldColumnName",
            schema: "dbo");
    }

Solution 4

To expand a bit on Hossein Narimani Rad's answer, you can rename both a table and columns using System.ComponentModel.DataAnnotations.Schema.TableAttribute and System.ComponentModel.DataAnnotations.Schema.ColumnAttribute respectively.

This has a couple benefits:

1. Not only will this create the the name migrations automatically, but
2. it will also deliciously delete any foreign keys and recreate them against the new table and column names, giving the foreign keys and constaints proper names.
3. All this without losing any table data

For example, adding [Table("Staffs")]:

[Table("Staffs")]
public class AccountUser
{
    public long Id { get; set; }

    public long AccountId { get; set; }

    public string ApplicationUserId { get; set; }

    public virtual Account Account { get; set; }

    public virtual ApplicationUser User { get; set; }
}

Will generate the migration:

    protected override void Up(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.DropForeignKey(
            name: "FK_AccountUsers_Accounts_AccountId",
            table: "AccountUsers");

        migrationBuilder.DropForeignKey(
            name: "FK_AccountUsers_AspNetUsers_ApplicationUserId",
            table: "AccountUsers");

        migrationBuilder.DropPrimaryKey(
            name: "PK_AccountUsers",
            table: "AccountUsers");

        migrationBuilder.RenameTable(
            name: "AccountUsers",
            newName: "Staffs");

        migrationBuilder.RenameIndex(
            name: "IX_AccountUsers_ApplicationUserId",
            table: "Staffs",
            newName: "IX_Staffs_ApplicationUserId");

        migrationBuilder.RenameIndex(
            name: "IX_AccountUsers_AccountId",
            table: "Staffs",
            newName: "IX_Staffs_AccountId");

        migrationBuilder.AddPrimaryKey(
            name: "PK_Staffs",
            table: "Staffs",
            column: "Id");

        migrationBuilder.AddForeignKey(
            name: "FK_Staffs_Accounts_AccountId",
            table: "Staffs",
            column: "AccountId",
            principalTable: "Accounts",
            principalColumn: "Id",
            onDelete: ReferentialAction.Cascade);

        migrationBuilder.AddForeignKey(
            name: "FK_Staffs_AspNetUsers_ApplicationUserId",
            table: "Staffs",
            column: "ApplicationUserId",
            principalTable: "AspNetUsers",
            principalColumn: "Id",
            onDelete: ReferentialAction.Restrict);
    }

    protected override void Down(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.DropForeignKey(
            name: "FK_Staffs_Accounts_AccountId",
            table: "Staffs");

        migrationBuilder.DropForeignKey(
            name: "FK_Staffs_AspNetUsers_ApplicationUserId",
            table: "Staffs");

        migrationBuilder.DropPrimaryKey(
            name: "PK_Staffs",
            table: "Staffs");

        migrationBuilder.RenameTable(
            name: "Staffs",
            newName: "AccountUsers");

        migrationBuilder.RenameIndex(
            name: "IX_Staffs_ApplicationUserId",
            table: "AccountUsers",
            newName: "IX_AccountUsers_ApplicationUserId");

        migrationBuilder.RenameIndex(
            name: "IX_Staffs_AccountId",
            table: "AccountUsers",
            newName: "IX_AccountUsers_AccountId");

        migrationBuilder.AddPrimaryKey(
            name: "PK_AccountUsers",
            table: "AccountUsers",
            column: "Id");

        migrationBuilder.AddForeignKey(
            name: "FK_AccountUsers_Accounts_AccountId",
            table: "AccountUsers",
            column: "AccountId",
            principalTable: "Accounts",
            principalColumn: "Id",
            onDelete: ReferentialAction.Cascade);

        migrationBuilder.AddForeignKey(
            name: "FK_AccountUsers_AspNetUsers_ApplicationUserId",
            table: "AccountUsers",
            column: "ApplicationUserId",
            principalTable: "AspNetUsers",
            principalColumn: "Id",
            onDelete: ReferentialAction.Restrict);
    }

Solution 5

Table names and column names can be specified as part of the mapping of DbContext. Then there is no need to do it in migrations.

public class MyContext : DbContext
{
    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Restaurant>()
            .HasMany(p => p.Cuisines)
            .WithMany(r => r.Restaurants)
            .Map(mc =>
            {
                mc.MapLeftKey("RestaurantId");
                mc.MapRightKey("CuisineId");
                mc.ToTable("RestaurantCuisines");
            });
     }
}

View more solutions

Comments

[Albin Sunnanbo]

Which of the above lines fails? Can you trace the migration in SQL Server Profiler and check the corresponding SQL?

[Ilan]

Be careful with table names which have dots in them. RenameColumn generates a sp_rename T-SQL statement which uses uses parsename internally which has some limitations. So if you have a table name which has dots in it e.g. "SubSystemA.Tablename" then use: RenameColumn("dbo.[SubSystemA.Tablename]", "OldColumnName", "NewColumnName");

[mikesigs]

This seems to update the columns referenced in the Foreign Keys, but it does not rename the FK itself. Which is a shame, but probably not the end of the world unless you absolutely need to refer to a FK later by its name.

[JoeBrockhaus]

@mikesigs you can use RenameIndex(..) in your migration to rename it

[CularBytes]

I can confirm this with 6.1.3 It does correctly rename the table (don't forget to rename the DbSet in your DatabaseContext as well). Changing the primary key does cause trouble. The migration will try to delete it and create a new one. So you need to adjust that and do as Chev's answer is, rename the column.

[Andrew S]

How are you able to add the same migration twice? When I try this, I get: The name 'Rename_SalesArea' is used by an existing migration.

[Hossein Narimani Rad]

have a look at -force parameter when using add-migration

[Andrew S]

docs.microsoft.com/en-us/ef/core/miscellaneous/cli/dotnet indicates that the --force parameter can only be applied to removing migrations. (Add-Migration is equivalent to dotnet ef migrations add)

[Hossein Narimani Rad]

have a look at the link you provide, It also Overwrite existing files.

[Hossein Narimani Rad]

also pay attention this post is not for EF core

[Crispy Ninja]

I think you only need one migration, but still two steps. 1. Add attribute and create "rename migration" 2. Just change the property name. That's it. Either way, this just saved me a ton of time. Thanks!

[Josue Martinez]

I am getting an exception when renaming column. probably because the rename table is still not applied. I had to divide it into two migrations

[patrick]

Seems like it should be the default to add the table attribute, makes things so much simpler.

[Mike]

And then you can remove the Column attribute to keep the code clean.

[derloopkat]

Okay, you can do this manually in console. But when you deploy these migrations using an automated tool, it's not going to compile twice for applying two migrations. It just gets the latest model and apply both migrations.

[Manojb86]

I followed the steps mentioned here and it was successful. I didn't lose any existing data. that what I really wanted, make the changes without losing the data. But I run the different migration after renaming the property name of the class, for the safe side.

[Giovanni]

With EF6, use RenameTable(..) to rename the FK's and PK's. Doesn't sound right but it's what worked for me. It's the method that creates the correct T-SQL (execute sp_rename ...). If you do update-database -verbose, you'll see it for yourself.

[Jonathan Wood]

That's great, except RenameTable and RenameColumn are undefined in Entity Framework Core.

[SixOThree]

This was definitely helpful. Adding [Column("NewName")] caused the migration to do a rename. Later when I renamed the property, the migration had nothing to do (which is good). Then after that I removed the [Column("NewName")], and the migration still have nothing to do (which is great).

[Sнаđошƒаӽ]

@JonathanWood RenameTable and RenameColumn in EF Core, and the documentation says these are there since EF core 1.0.Not sure what you are talking about.

[Rasmus Björling]

If you want to use this method for EF Core, definitely do the two steps with two separate migrations: ColumnChanged_A, then ColumnChanged_B. If you don't you risk having your DBModelSnapshot reference the old Property name. (maybe this will always sort itself in later migrations, but still seems kinda risky)

[Groo]

Thanks a lot, also just wanted to point out that after the first migration, you will typically remove the attribute and rename the table. It is very important to run one more migration at this point - you can name it "TempMigration" and then delete the actual migration afterwards, but it's important that the context snapshot gets updated with the new class name.

[Emulic]

@Groo, when I run the second migration after renaming the actual properties I see a drop table and stuff like that in the new migration script. You're saying that we can just discard that migration, and keep the snapshot, correct?

[Groo]

@Emulic: no, usually you shouldn't be getting any drop statements. So when you remove the attributes and rename the columns after the first migration, the next migration's Up and Down methods should be empty, just the snapshot file should be updated. Perhaps you need to check if all spelling is ok?

[Emulic]

@groo, thank you. Yeah, I realized I made a mistake with missing the plural s on the entity rename in step 1. After I fixed that after I created the migration at the end it was actually empty. Thanks on all the great info.

[Emulic]

I would suggest also checking out this answer that mentions renaming foreign key references: stackoverflow.com/a/49802766/103836

[fullStackChris]

This example only shows a table rename... does it work with table + column rename?

[Jyoti]

This worked just fine to rename the existing table. Thanks a lot !