prisma migrate diff

Compares database schemas and generates diffs (SQL or summary).

Command

prisma migrate diff [options]

What It Does

• Compares two sources (--from-... and --to-...)
• Sources can be:
  • Empty (empty)
  • Schema file (schema)
  • Migrations directory (migrations)
  • Database URL (url) or Configured Datasource (config-datasource)
• Outputs the difference:
  • Human-readable summary (default)
  • SQL script (--script)

Options

Sources (Must provide one from and one to)

• --from-empty, --to-empty
• --from-schema <path>, --to-schema <path>
• --from-migrations <path>, --to-migrations <path>
• --from-url <url>, --to-url <url>
• --from-config-datasource, --to-config-datasource (uses prisma.config.ts)

Examples

Generate SQL for a schema change

Compare current production DB to your local schema:

prisma migrate diff \
  --from-url "$PROD_DB_URL" \
  --to-schema ./prisma/schema.prisma \
  --script

Review pending migrations

Compare database state to migrations directory:

prisma migrate diff \
  --from-config-datasource \
  --to-migrations ./prisma/migrations

Create baseline migration

Compare empty state to current schema:

prisma migrate diff \
  --from-empty \
  --to-schema ./prisma/schema.prisma \
  --script > prisma/migrations/0_init/migration.sql

Check for drift (CI)

Check if database matches schema:

prisma migrate diff \
  --from-config-datasource \
  --to-schema ./prisma/schema.prisma \
  --exit-code

Use Cases

• Forward-generating migrations: Creating SQL without migrate dev.
• Drift detection: Checking if DB is in sync.
• Baselining: Creating initial migration from existing DB.
• Debugging: Understanding what migrate dev would do.