How to fix P3019: The datasource provider specified in your schema does not match the one specified in the migration_lock.toml in Prisma

Check your current schema.prisma configuration:

// prisma/schema.prisma
datasource db {
  provider = "postgresql"  // or "mysql", "sqlite", etc.
  url      = env("DATABASE_URL")
}

Then check the migration_lock.toml file:

cat prisma/migrations/migration_lock.toml

You'll see output like:

# Please do not edit this file manually
# It should be added in your version-control system (i.e. Git)
provider = "sqlite"

If the provider values don't match, that's the source of your error.

Determine which database provider you actually want to use. Consider:

- Development vs Production: Are you using different databases in different environments?
- Team Standards: What provider is your team standardized on?
- Migration History: Do you need to preserve existing migrations?

If you're switching providers intentionally, be aware that you'll need to reset your migration history. If this was accidental, revert to the correct provider in your schema.

If you accidentally changed the provider and want to go back:

1. Update your schema.prisma to match migration_lock.toml:

datasource db {
  provider = "postgresql"  // Match what's in migration_lock.toml
  url      = env("DATABASE_URL")
}

2. Update your DATABASE_URL environment variable to point to the correct database type.

3. Run migrations:

npx prisma migrate deploy

This approach preserves your migration history and data.

If you genuinely need to switch to a different database provider:

1. Backup your data if you have any important data in your current database.

2. Delete the migrations folder:

rm -rf prisma/migrations

3. Update your schema.prisma with the new provider:

datasource db {
  provider = "mysql"  // Your new provider
  url      = env("DATABASE_URL")
}

4. Update your DATABASE_URL to point to the new database.

5. Create a fresh migration history:

npx prisma migrate dev --name init

This creates new migrations for the new provider and a new migration_lock.toml file.

Only do this if you're absolutely certain the existing migrations are compatible with your new provider (rare):

1. Edit prisma/migrations/migration_lock.toml:

# Please do not edit this file manually
# It should be added in your version-control system (i.e. Git)
provider = "postgresql"  # Change to your desired provider

2. Run:

npx prisma migrate resolve --applied <migration-name>

Warning: This is risky and can lead to migration failures. Only use this if you have simple migrations with compatible SQL across providers.

After applying your chosen solution, verify everything works:

# Check migration status
npx prisma migrate status

# Generate Prisma Client
npx prisma generate

# Test database connection
npx prisma db pull

All commands should complete without the P3019 error.