Entity Framework rollback and remove bad migration

Question

I m using EF 6 0 for my project in C  with manual migrations and updates  I have about 5 migrations on the database  but I realised that the last migration was bad and I don t want it  I know that I can rollback to a previous migration  but when I add a new  fixed  migration and run Update-Database  even the bad migration is applied   I was trying to rollback to the previous migration and delete the file with bad migration  But then  when I try to add new migration  I get error when updating database  because the migration file is corrupted  more specifically  first line of code rename the table A to B  and is next lines  EF is trying to update table with name A - maybe it is some EF bug    Is there some query I can run  which would tell EF something like  Forget last migration like it never existed  it was bad   Something like Remove-Migration   Edit1 I found solution suited for me  Changing model to the good state and run Add-Migration TheBadMigration -Force  This will re-scaffold the last  not applied migration   Anyway  this still not answer the original question completely  If I UpdateDatabase to the bad migration  I did not found good way how to rollback and create new migration  excluding the bad one    Thanks

User · Answer

You have 2 options     You can take the Down from the bad migration and put it in a new migration  you will also need to make the subsequent changes to the model   This is effectively rolling up to a better version    I use this option on things that have gone to multiple environments  The other option is to actually run Update-Database    TargetMigration  TheLastGoodMigration against your deployed database and then delete the migration from your solution  This is kinda the hulk smash alternative and requires this to be performed against any database deployed with the bad version   Note  to rescaffold the migration you can use Add-Migration  existingname  -Force  This will however overwrite your existing migration  so be sure to do this only if you have removed the existing migration from the database  This does the same thing as deleting the existing migration file and running add-migration  I use this option while developing

User · Answer

First  Update your last perfect migration via this command     Update-Database    TargetMigration   Example   Update-Database -20180906131107 xxxx xxxx   And  then delete your unused migration manually

User · Answer

As of  NET Core 2 2  TargetMigration seems to be gone   get-help Update-Database  NAME     Update-Database  SYNOPSIS     Updates the database to a specified migration    SYNTAX     Update-Database   -Migration   lt String gt    -Context  lt String gt    -Project  lt String gt    -StartupProject  lt String gt     lt CommonParameters gt     DESCRIPTION     Updates the database to a specified migration    RELATED LINKS     Script-Migration     about EntityFrameworkCore   REMARKS     To see the examples  type   get-help Update-Database -examples       For more information  type   get-help Update-Database -detailed       For technical information  type   get-help Update-Database -full       For online help  type   get-help Update-Database -online    So this works for me now   Update-Database -Migration 20180906131107 xxxx xxxx   As well as  no -Migration switch    Update-Database 20180906131107 xxxx xxxx   On an added note  you can no longer cleanly delete migration folders without putting your Model Snapshot out of sync  So if you learn this the hard way and wind up with an empty migration where you know there should be changes  you can run  no switches needed for the last migration    Remove-migration   It will clean up the mess and put you back where you need to be  even though the last migration folder was deleted manually

User · Answer

As the question indicates this applies to a migration in a development type environment that has not yet been released  This issue can be solved in these steps  restore your database to the last good migration  delete the bad migration from your Entity Framework project  generate a new migration and apply it to the database  Note  Judging from the comments these exact commands may no longer be applicable if you are using EF Core  Step 1  Restore to a previous migration If you haven t yet applied your migration you can skip this part  To restore your database schema to a previous point issue the Update-Database command with -TargetMigration option specify the last good migration  If your entity framework code resides in a different project in your solution  you may need to use the  -Project  option or switch the default project in the package manager console  Update-Database    TargetMigration   lt name of last good migration gt   To get the name of the last good migration use the  Get-Migrations  command to retrieve a list of the migration names that have been applied to your database  PM gt  Get-Migrations Retrieving migrations that have been applied to the target database  201508242303096 Bad Migration 201508211842590 The Migration applied before it 201508211440252 And another  This list shows the most recent applied migrations first  Pick the migration that occurs in the list after the one you want to downgrade to  ie the one applied before the one you want to downgrade  Now issue an Update-Database  Update-Database    TargetMigration   quot  lt the migration applied before it gt  quot   All migrations applied after the one specified will be down-graded in order starting with the latest migration applied first  Step 2  Delete your migration from the project remove-migration name of bad migration  If the remove-migration command is not available in your version of Entity Framework  delete the files of the unwanted migration your EF project  Migrations  folder manually  At this point  you are free to create a new migration and apply it to the database  Step 3  Add your new migration add-migration my new migration  Step 4  Apply your migration to the database update-database

User · Answer

For EF 6 here s a one-liner if you re re-scaffolding a lot in development   Just update the vars and then keep using the up arrow in package manager console to rinse and repeat    lastGoodTarget    OldTargetName    newTarget    NewTargetName   Update-Database -TargetMigration   lastGoodTarget  -Verbose  Add-Migration   newTarget  -Verbose -Force   Why is this necessary you ask  Not sure which versions of EF6 this applies but if your new migration target has already been applied then using  -Force  to re-scaffold in Add-Migration will not actually re-scaffold  but instead make a new file  this is a good thing though because you wouldn t want to lose your  Down     The above snippet does the  Down  first if necessary then -Force works properly to re-scaffold

User · Answer

You can also use  Remove-Migration -Force   This will revert and remove the last applied migration

User · Answer

I am using EF Core with ASP NET Core  V2 2 6   Richard Logwood s answer was great and it solved my problem  but I needed a different syntax  So  For those using EF Core with ASP NET Core  V2 2 6      instead of Update-Database  lt Name of last good migration gt   I had to use  dotnet ef database update  lt Name of last good migration gt   And instead of Remove-Migration  I had to use  dotnet ef migrations remove  For --help i had to use   dotnet ef migrations --help   Usage  dotnet ef migrations  options   command   Options    -h --help        Show help information   -v --verbose     Show verbose output    --no-color       Don t colorize output    --prefix-output  Prefix output with level   Commands    add     Adds a new migration    list    Lists available migrations    remove  Removes the last migration    script  Generates a SQL script from migrations   Use  quot migrations  command  --help quot  for more information about a command   This let me role back to the stage where my DB worked as expected  and start from beginning

User · Answer

For those using EF Core with ASP NET Core v1 0 0 I had a similar problem and used the following commands to correct it   DavidSopko s post pointed me in the right direction  but the details are slightly different for EF Core    Update-Database  lt Name of last good migration gt  Remove-Migration   For example  in my current development the command became  PM gt  Update-Database CreateInitialDatabase Done  PM gt  Remove-Migration Done  PM gt     The Remove-Migration will remove the last migration you applied  If you have a more complex scenario with multiple migrations to remove  I only had 2  the initial and the bad one   I suggest you test the steps in a dummy project   There doesn t currently appear to be a Get-Migrations command in EF Core  v1 0 0  so you must look in your migrations folder and be familiar with what you have done  However  there is a nice help command   PM gt  get-help entityframework   Refreshing dastabase in VS2015 SQL Server Object Explorer  all of my data was preserved and the migration that I wanted to revert was gone     Initially I tried Remove-Migration by itself and found the error command confusing      System InvalidOperationException  The migration       has already been   applied to the database  Unapply it and try again  If the migration   has been applied to other databases  consider reverting its changes   using a new migration    There are already suggestions on improving this wording  but I d like the error to say something like this      Run Update-Database  last good migration name  to revert the database schema back to to that state  This command will   unapply all migrations that occurred after the migration specified to   Update-Database  You may then run Remove-Migration  migration name to remove    Output from the EF Core help command follows    PM gt  get-help entityframework                                           ---                                                                                                                                           TOPIC     about EntityFrameworkCore  SHORT DESCRIPTION     Provides information about Entity Framework Core commands   LONG DESCRIPTION     This topic describes the Entity Framework Core commands  See https   docs efproject net for information on Entity Framework Core       The following Entity Framework cmdlets are included           Cmdlet                      Description         --------------------------  ---------------------------------------------------         Add-Migration               Adds a new migration           Remove-Migration            Removes the last migration           Scaffold-DbContext          Scaffolds a DbContext and entity type classes for a specified database           Script-Migration            Generates a SQL script from migrations           Update-Database             Updates the database to a specified migration           Use-DbContext               Sets the default DbContext to use   SEE ALSO     Add-Migration     Remove-Migration     Scaffold-DbContext     Script-Migration     Update-Database     Use-DbContext

[c#] Entity Framework rollback and remove bad migration

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