# Drizzle app database

Eristack packages expose **table factories** under `@eristack/*/drizzle`. They **never** open connections, read `DATABASE_URL`, or run migrations. The app owns one boot path.

## `openDrizzle`

```ts
import * as schema from "./schema.js";
import { openDrizzle } from "@eristack/drizzle";

export const databasePromise = openDrizzle({
  schema,
  migrationsFolder: { sqlite: "./drizzle/sqlite", pgsql: "./drizzle/pgsql" },
});
```

Returns `{ db, dialect, location, close }`:

- **dialect** — `sqlite` | `pgsql` from `APP_DB_DIALECT`, else Postgres URL heuristic, else sqlite.
- **location** — sqlite file path or **redacted** Postgres URL (safe for `@eristack/health`).
- **Drivers** — lazy `better-sqlite3` / `pg` so Postgres deploys do not load the SQLite native module.

Pool defaults: `max: 5`, `idleTimeoutMs: 30_000`. Pass `migrate: false` in tests when you do not need migrator I/O.

## Compose schema

1. App `schema.ts` calls `createJwtAuthTables(dialect)`, `createRbacTables(dialect)`, … plus business tables.
2. `@eristack/drizzle-kit-helpers` — drizzle-kit config for two `out` folders.
3. Inject `db` into Express/Nest compose — see `examples/express/src/db/client.ts` (`bootAppDatabase` → `openDrizzle`).

## Step 2 — `@eristack/drizzle/schema`

```ts
import { createEristackSpineTables, dialectJsonMap, dialectText, entityIdColumn } from "@eristack/drizzle/schema";

const DIALECT = resolveAppDbDialect(); // or env constant in schema.ts

export const spine = createEristackSpineTables({ dialect: DIALECT, backseatDocuments: true });
```

Column helpers: `dialectText`, `dialectFlag`, `dialectJson`, `dialectStringList`, `dialectJsonMap`, `dialectTimestampJson`, plus `entityIdColumn` re-export. Spine composes jwt-auth, rbac, epoch, doc-number, optional backseat documents — app still owns `users` and business tables. Folds `20260925-201504` into this package, not a second bootstrap package.

**B4** — `defineErpCollection` / `erpCollectionManifests` on `@eristack/drizzle/schema` + `#collection-declaration-horizon-b`. Mirror CI via `@eristack/backseat/testing`; SQL codegen from manifests is later.

## Do not

- Open Drizzle from feature packages or jwt-auth internals.
- Duplicate `createAppDatabase` in every app without reading this guide — copy `openDrizzle` once at the compose root.