entity framework - EF Migrations: Rollback last applied migration?

Question

This looks like a really common task, but I can't find an easy way to do it.

I want to undo the last applied migration. I would have expected a simple command, like

PM> Update-Database -TargetMigration:"-1"

Instead, all I can come up with is:

PM> Get-Migrations

Retrieving migrations that have been applied to the target database.
201208012131302_Add-SystemCategory
201207311827468_CategoryIdIsLong
201207232247409_AutomaticMigration
201207211340509_AutomaticMigration
201207200025294_InitialCreate

PM> Update-Database -TargetMigration:"CategoryIdIsLong"

(At least I can use just the name, skipping the timestamp...)

Is there an easier way?

Answer 1

I want to add some clarification to this thread:

Update-Database -TargetMigration:"name_of_migration"

What you are doing above is saying that you want to rollback all migrations UNTIL you're left with the migration specified. Thus, if you use GET-MIGRATIONS and you find that you have A, B, C, D, and E, then using this command will rollback E and D to get you to C:

Update-Database -TargetMigration:"C"

Also, unless anyone can comment to the contrary, I noticed that you can use an ordinal value and the short -Target switch (thus, -Target is the same as -TargetMigration). If you want to rollback all migrations and start over, you can use:

Update-Database -Target:0

0, above, would rollback even the FIRST migration (this is a destructive command--be sure you know what you're doing before you use it!)--something you cannot do if you use the syntax above that requires the name of the target migration (the name of the 0th migration doesn't exist before a migration is applied!). So in that case, you have to use the 0 (ordinal) value. Likewise, if you have applied migrations A, B, C, D, and E (in that order), then the ordinal 1 should refer to A, ordinal 2 should refer to B, and so on. So to rollback to B you could use either:

Update-Database -TargetMigration:"B"

or

Update-Database -TargetMigration:2

Edit October 2019:

According to this related answer on a similar question, correct command is -Target for EF Core 1.1 while it is -Migration for EF Core 2.0.