Configure drizzle.config.ts and use `drizzle-kit generate` to turn changes in a Drizzle TypeScript schema into versioned SQL migration files without touching the database.

Documented steps

1. Install drizzle-kit as a dev dependency and drizzle-orm as a regular dependency: `npm i -D drizzle-kit` and `npm i drizzle-orm`.
2. Create `drizzle.config.ts` at the project root using `defineConfig` from "drizzle-kit". Set `dialect` (one of `postgresql`, `mysql`, `sqlite`, `turso`, `singlestore`, `mssql`, `cockroach`) and `schema` (glob path to schema file(s)), e.g.: `import { defineConfig } from "drizzle-kit"; export default defineConfig({ dialect: "postgresql", schema: "./src/schema.ts", out: "./drizzle" });`
3. Write/modify your Drizzle schema file(s) referenced by `schema` (e.g. `src/schema.ts`) using the dialect's table helpers (`pgTable`, `mysqlTable`, `sqliteTable`, etc.).
4. Run `npx drizzle-kit generate` to produce migrations. Add `--name=<name>` for a custom migration name, e.g. `npx drizzle-kit generate --name=init`.
5. Drizzle Kit reads previous migration folders, diffs against the current schema snapshot, may prompt for renames, then writes `drizzle/<timestamp>_<name>/migration.sql` and `snapshot.json`.
6. For multiple environments/databases, pass `--config=<path>`, e.g. `npx drizzle-kit generate --config=drizzle-prod.config.ts`, keeping a separate config file per environment.
7. Commit the generated migration folder to version control; it is the history that `drizzle-kit migrate` and `drizzle-kit check` rely on.
8. Reference: https://orm.drizzle.team/docs/drizzle-kit-generate https://orm.drizzle.team/docs/drizzle-config-file https://orm.drizzle.team/docs/migrations