Database schema diff

What is a database schema diff?

A database schema diff compares the structure of two databases — or two versions of the same database — and highlights exactly what changed. Unlike a text diff, which compares raw characters, a schema diff understands tables, columns, types, and constraints, giving you a semantic view of structural changes.

When to use a schema diff tool

• Auditing migration files — paste the before and after states to verify the migration does what you expect
• Code reviews — compare the schema changes in a pull request without mentally parsing raw DDL
• Debugging production issues — compare the production schema with staging or development to find unexpected drift
• Documenting schema evolution over time for compliance or onboarding
• Validating ORM-generated migrations against hand-written DDL

How the comparison works

The tool parses both schemas, extracts each CREATE TABLE statement, and builds a map of tables to columns (with types, constraints, and defaults). It then performs a structural comparison: new tables, dropped tables, new columns, dropped columns, and type or constraint changes are all identified and displayed in a clear report.

Track schema changes automatically with Basedash

Rather than manually diffing schemas, Basedash connects directly to your database and gives you a live view of tables, columns, and relationships. When your schema changes, Basedash reflects the new structure automatically — no manual exports or paste-and-compare needed.