I've mucked up my migrations, I used IgnoreChanges
on the initial migration, but now I want to delete all my migrations and start with an initial migration with all of the logic.
When I delete the migrations in the folder and try and Add-Migration
it doesn't generate a full file (it's empty - because I haven't made any changes since my last, but now deleted, migration).
Is there any Disable-Migrations command, so I can rerun Enable-Migrations
?
This question is related to
entity-framework
database-migration
entity-framework-migrations
The Issue: You have mucked up your migrations and you would like to reset it without deleting your existing tables.
The Problem: You can't reset migrations with existing tables in the database as EF wants to create the tables from scratch.
What to do:
Delete existing migrations from Migrations_History table.
Delete existing migrations from the Migrations Folder.
Run add-migration Reset. This will create a migration in your Migration folder that includes creating the tables (but it will not run it so it will not error out.)
You now need to create the initial row in the MigrationHistory table so EF has a snapshot of the current state. EF will do this if you apply a migration. However, you can't apply the migration that you just made as the tables already exist in your database. So go into the Migration and comment out all the code inside the "Up" method.
Now run update-database. It will apply the Migration (while not actually changing the database) and create a snapshot row in MigrationHistory.
You have now reset your migrations and may continue with normal migrations.
In Entity Framework Core.
Remove all files from migrations folder.
Type in console
dotnet ef database drop -f -v
dotnet ef migrations add Initial
dotnet ef database update
UPD: Do that only if you don't care about your current persisted data. If you do, use Greg Gum's answer
In EntityFramework 6 please try:
Add-Migration Initial
in order to update the initial migration file.
Delete the Migrations
Folder, Clean
then Rebuild
the project. This worked for me. Before Clean and Rebuild it was saying the Migration already exists since in its cached memory, it's not yet deleted.
UPDATE 2020 => Reset Entity-Framework Migrations
Add-Migration Initial -Context ApplicationDbContext
ApplicationDbContext => Your context.
But if you need only update a identity schema existent, try it: https://stackoverflow.com/a/59966100/4654957
My problem turned out to be that I manually removed the Migrations folder. I did that because I wanted to back up the contents, so I simply dragged the folder out of the project. I later fixed the problem by putting it back in (after making a backup copy), then removing the Migrations folder by right-clicking it in Solutions Explorer and choosing Delete from the popup menu.
Considering this still shows up when we search for EF in .NET Core, I'll post my answer here (Since it has haunted me a lot). Note that there are some subtleties with the EF 6 .NET version (No initial command, and you will need to delete "Snapshot" files)
(Tested in .NET Core 2.1)
Here are the steps:
_efmigrationhistory
table.ApplicationDbContextSnapshot.cs
, and delete them.Add-Migration InitialMigration
Please note: You must delete ALL the Snapshot files. I spent countless hours just deleting the database... This will generate an empty migration if you don't do it.
Also, in #3 you can just name your migration however you want.
Here are some additional resources: asp.net CORE Migrations generated empty
How about
Update-Database –TargetMigration: $InitialDatabase
in Package Manager Console? It should reset all updates to its very early state.
Reference link: Code First Migrations - Migrating to a Specific Version (Including Downgrade)
In Net Core 3.0:
I was not able to find a way to Reset Migrations.
I also ran into problems with broken migrations, and the answers provided here didn't work for me. I have a .Net Core 3.0 web API, and somewhere in the last month I edited the database directly. Yes, I did a bad, bad thing.
Strategies suggested here resulted in a number of errors in Package Manager Console:
Granted, I may have missed a step or missed clearing out the correct files, but I found that there are ways to clean this up without as much brute force:
Now when the web API is started with an empty database, it correctly creates all the tables and properties to match the entity models.
HTH!
This method doesn't require deleting of the __MigrationHistory
table, so you don't have to put your hands on the database on deploy.
Add-Migration ResetMigrations
Up()
method:/// <summary>
/// Reset existing migrations by cleaning the __MigrationHistory table
/// and creating a new initial migration with the current model snapshot.
/// </summary>
public partial class ResetMigrations : DbMigration
{
public override void Up()
{
Sql("DELETE FROM [dbo].[__MigrationHistory]");
}
public override void Down()
{
}
}
Enable-Migrations -EnableAutomaticMigrations -Force
In EF6
Add-Migration Initial
.To fix this, You need to:
Delete all *.cs files in the Migrations Folder.
Delete the _MigrationHistory Table in the Database
Run Enable-Migrations -EnableAutomaticMigrations -Force
Run Add-Migration Reset
Then, in the public partial class Reset : DbMigration
class, you need to comment all of the existing and current Tables:
public override void Up()
{
// CreateTable(
// "dbo.<EXISTING TABLE NAME IN DATABASE>
// ...
// }
...
}
If you miss this bit all will fail and you have to start again!
Update-Database -verbose
This should be successful if you have done the above correctly, and now you can carry on as normal.
Source: Stackoverflow.com