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SQL

An alchemy app talks SQL at whichever level fits: a raw tagged-template client, an ORM, or both against the same connection. The schema rides the same deploy graph as the infrastructure, so alchemy deploy regenerates and applies pending migrations alongside everything else.

Databases

Section titled “Databases”
  • D1 — Cloudflare’s serverless SQLite, bound natively into a Worker.
  • Hyperdrive — edge connection pooling for any Postgres or MySQL: Neon, PlanetScale, RDS, or a database you already run.
  • AWS-side connections — DSQL, RDS, and Redshift bindings in the API reference.

Clients

Section titled “Clients”

alchemy/SQL/* is the low-level home: tagged-template queries with typed errors, no ORM — one subpath per backend (alchemy/SQL/D1, alchemy/SQL/Postgres, alchemy/SQL/MySQL), so you only load the driver you use. alchemy/Drizzle is the ORM sibling: a typed schema and relational queries. Drizzle.Schema, Drizzle.providers(), and Drizzle.D1 come from the alchemy/Drizzle entry; the Postgres and MySQL clients live on their own subpaths (alchemy/Drizzle/Postgres, alchemy/Drizzle/MySQL) so their drivers only load when you use them, and the Durable Object client lives at alchemy/Drizzle/Cloudflare. Both wrap the same @effect/sql drivers and share one lifecycle.

import * as SQL from "alchemy/SQL/D1";
import * as Drizzle from "alchemy/Drizzle";


// Raw effect-sql — tagged-template queries, typed errors
const sql = yield* SQL.D1(d1);
const users = yield* sql`SELECT * FROM users WHERE id = ${id}`;


// Drizzle — typed schema, relational queries
const db = yield* Drizzle.D1(d1, { relations });
const user = yield* db.query.Users.findFirst({ with: { posts: true } });

Every client builds lazily on the first query of an execution, is reused for every query in that execution, and tears down when the event settles — Connection lifecycle explains why.

What are you building?

Section titled “What are you building?”
Goal Reach for
Raw SQL on Postgres Effect SQL: Postgres
Raw SQL on MySQL Effect SQL: MySQL
Raw SQL on D1 Effect SQL: D1
Typed schema + queries on Postgres Drizzle: Postgres
Typed schema + queries on MySQL Drizzle: MySQL
Typed schema + queries on D1 Drizzle: D1
Schema changes applied on deploy Drizzle migrations
Hand-written .sql migrations Effect SQL migrations
A service that runs on any database SqlClient + Layers — see Provide as a service

Where next

Section titled “Where next”