How does Drizzle handle schema migrations?

Question

RepoPilot · Accepted Answer

Based on the repository data, Drizzle handles schema migrations through **Drizzle Kit**, a powerful CLI companion tool mentioned in the README [README.md:L29-L35].

Here's how migrations work in Drizzle:

## Separated Migration Imports

Starting from version 0.14.0, Drizzle separated migrations functionality into dedicated imports. For example:

- **PostgreSQL**: `import { migrate } from 'drizzle-orm-pg/node/migrate';` [changelogs/drizzle-orm-pg/0.14.0.md:L3-L5]
- **SQLite**: `import { migrate } from 'drizzle-orm-sqlite/better-sqlite3/migrate';` [changelogs/drizzle-orm-sqlite/0.14.1.md:L3-L5]

## Drizzle Kit's Migration Capabilities

According to the README, **Drizzle Kit can**:
- Generate SQL migration files automatically
- Apply schema changes directly to the database [README.md:L31-L32]

## Schema Definition & Code Generation

The `drizzle-kit export` command translates your Drizzle schema into SQL DDL statements. For example, a TypeScript table definition gets converted to CREATE TABLE SQL [changelogs/drizzle-kit/0.30.1.md:L3-L35].

## Configuration Support

Drizzle Kit supports configuration options like:
- **`casing` parameter**: Automatically maps naming conventions (e.g., `camelCase` in code to `snake_case` in the database) [changelogs/drizzle-kit/0.25.0.md:L146-L180]
- **`dialect` specification**: Supports PostgreSQL, MySQL, SQLite, and Gel dialects [changelogs/drizzle-kit/0.30.5.md:L3-L30]

FOLLOW_UPS:
- What SQL features does Drizzle support?
- How do you connect Drizzle to different databases?
- What is Drizzle Studio used for?