Migrations — Changing Your Database Without Losing Data

Your app is live. Real users have real data in your database. Now you need to add a new feature that requires a new column. Or rename a table. Or change a column type.

You can't just drop the table and recreate it — there's data in there. You can't manually run SQL on production and hope you remember what you did — that's how you get environments that are subtly different and impossible to debug.

Migrations solve this. They're versioned, trackable, reversible scripts that evolve your database schema over time.

What Is a Migration?

A migration is a file that describes a change to your database schema. Each migration has:

• A version number or timestamp so they run in order
• An up function that applies the change
• A down function that reverses it

-- Migrati