Prisma Migrate: false positive drift detection on `foreign keys` when is used with an existing database

Bug description

When trying to use Prisma with an existing database I can get the migrations in sync without being forced to reset the database. I have a big DB schema but I will refer just to one table called user, because the issue is the same for all foreign keys and unique indexes.

After I run prisma migrate dev --name initial-migration --create-only, I get the following error:

? Drift detected: Your database schema is not in sync with your migration history.

[+] Added tables
  - user

[*] Changed the `user` table
  [+] Added unique index on columns (email)
  [+] Added foreign key on columns (profileId)

We need to reset the PostgreSQL database "my_database" at "localhost:5432".
Do you want to continue? All data will be lost. › (y/N)

The closest I got to the desired behaviour was:

1. Export just the data with pg_dump
2. prisma migrate dev --name initial-migration --create-only and press y to allow my database to be formatted
3. Import my data back

Now everything is working but I don’t want to do this in production as we have a database with 100GB+ of data and I am not sure if something was affected.

Another weird thing is that, I have compared the database schema created by Prisma with my old one and no change. Same for schema.prisma. So I am inclined to think that it’s a bug.

Extra details

• After I fixed everything, as I described above, I’ve decided to delete the migrations + the prima migration table. And to try one more time to see if the database schema was the problem but I got the same error. So it seems that migrate is rejecting any foreign key if it’s not in its migration files. Just an assumption, maybe it will help you.
• I use DataGrip as a viewer for the data and even with their differences viewer tool I couldn’t detect any difference between my old schema and the one pushed by Prisma.

PS: I can fix the “Added unique index on columns” error by changing the index name. But the one with foreign key I have no clue on what’s wrong. As stated above, I have double checked my constrain vs the one generated by Prisma. 0 differences.

How to reproduce

Steps followed

1. prisma init
2. prisma introspect - the schema.prisma is generated
3. prisma generate
4. prisma migrate dev --name initial-migration --create-only

Expected behavior

Is expected that Prisma will generate the migration file after running prisma migrate dev --name initial-migration --create-only.

Prisma information

A simple table of users with an id, email (w/ a unique constraint) and a profileId which is a foreign key to the second table called profiles which contains an id and a name field.

Environment & setup

• OS: Mac OS
• Database: PostgreSQL
• Node.js version: v14.17.2

Prisma Version

Tested with v2.23.0 until v2.26.0

[janpio]

Wow, what an amazing post. I just skimmed it, someone else will read it in more detail, but a thought: Are you trying to baseline your database in step 9? https://www.prisma.io/docs/guides/database/developing-with-prisma-migrate/baselining Or are you just trying to use the tools you know about in Prisma land and then you end up in the situation you describe?

[Gamote]

Wow, what an amazing post. I just skimmed it, someone else will read it in more detail, but a thought: Are you trying to baseline your database in step 9? https://www.prisma.io/docs/guides/database/developing-with-prisma-migrate/baselining Or are you just trying to use the tools you know about in Prisma land and then you end up in the situation you describe?

@janpio Yup, I’m trying to baseline.