Adding `enum` value as part of data migration breaks running servers about prisma HOT 4 OPEN

Do I understand that you start a server running Prisma schema version 1, then migrate the database to Prisma schema version 2, change the data in the database to use an enum value of Prisma schema version 2, and then your already running server fails as it can not handle the new enum value that is being return for queries that concern the data that was changed?

from prisma.

Do I understand that you start a server running Prisma schema version 1, then migrate the database to Prisma schema version 2, change the data in the database to use an enum value of Prisma schema version 2, and then your already running server fails as it can not handle the new enum value that is being return for queries that concern the data that was changed?

Exactly!

If this is intended behavior feel free to change this issue to a feature request, i.e. to not throw error and instead ignore rows containing unknown enum values.

from prisma.

How would you expect Prisma to deal with the invalid data then?
How would your app deal with the data to be missing for this field?

from prisma.

I think this is currently expected.

Because the Prisma Client was generated with the given enum in the schema

enum MyEnum {
  A
}

And does not know about the new enum value yet.

So after updating your Prisma schema and applying the migration you must also re-generate the Prisma Client with npx prisma generate

from prisma.