`prisma db push` generating identifier names longer than 64 characters

Bug description

I have relations between complex objects that generates long identifier names. While executing prisma db push Prisma appends ‘_ibfk_1’ even if it will have more than 64 characters after appending. My use case is to be used by Jest for pushing the schema into test database.

It rejects promise:

Promise {
        <rejected> Error: Command failed: /Users/../../../node_modules/.bin/prisma db push --preview-feature
        Error: Database error: Error querying the database: Server error: `ERROR 42000 (1059): Identifier name 'foundation_variable_set_foundation_configuration_values_aud_ibfk_1' is too long'
           0: sql_migration_connector::sql_database_step_applier::apply_step
                   with index=0
                     at migration-engine/connectors/sql-migration-connector/src/sql_database_step_applier.rs:14
           1: migration_core::api::SchemaPush
                     at migration-engine/core/src/api.rs:166

How to reproduce

1. Have a Prisma schema in which there are table names with length larger than 57 characters (64 - 7) as ‘_ibfk_1’ has 7 characters.
2. run prisma db push --preview-feature
3. Expect an error to be thrown

Expected behavior

Generate an alternative name which is shorter than 64 characters, or Let the user choose custom name for the identifier

In my case I can’t really change the MySQL schema and I need to work with what I have. I know these names are unnecessary and repetitive but that’s what Prisma generates.

Prisma information

The schema is pretty big so I include the part of it:

model foundation_variable_set_foundation_configuration_values_aud {
  REV                Int
  CompanyVariable_id Int
  valueList_id       Int
  REVTYPE            Int?
  DeviceVariable_id  Int
  GroupVariable_id   Int
  revinfo            revinfo @relation(fields: [REV], references: [REV])

  @@id([REV, GroupVariable_id, valueList_id])
}

Environment & setup

• OS: MacOS
• Database: MySQL
• Node.js version: 12.16.1
• Prisma version: 12.15.0

[do4gr]

A fix for this issue is now available via the namedConstraints preview flag since 2.29. It implements both solutions mentioned above, a default name generation that respects db name length limits and the option for user-specified names.

See https://www.prisma.io/docs/guides/upgrade-guides/upgrading-to-use-preview-features/enabling-named-constraints

[tomhoule]

This is currently being worked on, expect a preview feature to make it into a release soon.