PlanetScale Foreign Key Constraints Not Working

How to fix it

Try these in order — the most common fix is first.

1. 1. Enable foreign key constraints

   Copy steps
   1. Open your database > Settings
   2. Turn on foreign key constraints support
   3. Retry the deploy request
   Did this fix it? Yes No

2. 2. Split the change

   Copy steps
   1. Deploy parent table changes first
   2. Add child constraints in a later deploy request
   Did this fix it? Yes No

3. 3. Break circular references

   Copy steps
   1. Drop one of the circular constraints
   2. Keep a plain index on the column and enforce the rule in the app
   Did this fix it? Yes No

Symptoms

Schema changes fail with FOREIGN_KEYS_CIRCULAR_DEPENDENCY or FOREIGN_KEYS_UNRESOLVED, or constraints are rejected.

Why it happens

• Foreign key support not turned on
• Circular dependencies between tables
• Parent and child tables changed in the same deploy request

This guide also covers

• planetscale foreign keys
• planetscale foreign key constraint error

Other PlanetScale errors

• PlanetScale Transaction Pool Connection Limit Exceeded
• PlanetScale Safe Migrations: DDL Statement Rejected
• PlanetScale Prisma Connection Errors
• PlanetScale Query Exceeded Row or Time Limit
• PlanetScale Postgres Import Fails or Is Slow
• PlanetScale Postgres Extension Not Available
• PlanetScale Unexpected Bill: Storage, Backups and Transfer
• PlanetScale Connection Errors During Outage