Drizzle MySQL on Railway

Run Drizzle in a Railway container beside Railway MySQL. Start with Railway setup, the Service tutorial, and a src/schema.ts exporting a MySQL Users table from the MySQL client guide.

Install the database dependencies

pnpm add drizzle-orm@1.0.0-rc.5-ab785fc @effect/sql-mysql2 mysql2
pnpm add -D drizzle-kit@1.0.0-rc.5-ab785fc

The Drizzle versions match the repository’s Effect integration.

Configure migrations

drizzle.config.ts

import { defineConfig } from "drizzle-kit";

export default defineConfig({
  dialect: "mysql",
  schema: "./src/schema.ts",
  out: "./drizzle",
  dbCredentials: { url: process.env.DATABASE_URL! },
});

DATABASE_URL here is a MySQL URL for the migration runner, separate from the Service’s bound MYSQL_URL.

Generate after changing the schema

pnpm exec drizzle-kit generate

Review the generated SQL and snapshots, including any rename decisions, before applying them.

Commit the migration

git add src/schema.ts drizzle.config.ts drizzle
git diff --cached

git commit -m "Add users migration"

Commit the schema, SQL, and snapshots together; deployment must consume the reviewed history.

Declare MySQL

src/db.ts

import * as Railway from "alchemy/Railway";
import { Site } from "./project.ts";

export const Db = Railway.MySQL("Db", { project: Site });

This creates the MySQL service, persistent volume, and a public TCP proxy by default; keep the database and application in the same Railway environment.

Install the driver in the Service image

src/api.ts

{
  project: Site,
  main: import.meta.url,
  build: { install: ["mysql2"] },
}

Use the container-backed Railway.Service packaging path, not the single-file Canvas Railway.Function path.

Bind MySQL

import { Db } from "./db.ts";

Effect.gen(function* () {
  const conn = yield* Railway.ConnectMySQL(Db);
  return {
    fetch: Effect.succeed(HttpServerResponse.text("Hello from Railway!")),
  };
}),
}).pipe(Effect.provide(Railway.ConnectMySQLHttp)),

The binding supplies an Effect-valued, redacted private connection string rather than a SQL query method. These excerpts use the tutorial’s minimal text handler until the database is migrated.

Provision before the first migration

pnpm alchemy deploy

Keep yield* Api in the tutorial’s Stack with Railway.providers(). The initial handler does not query tables, so the database can be provisioned before its first migration.

Apply the committed SQL

pnpm exec drizzle-kit migrate

Supply publicConnectionUri as secret DATABASE_URL for an external runner, or run inside the same Railway environment with connectionUri when public: false. Configure and verify TLS for any public database traffic; do not disable certificate verification to make a migration connect.

Open the runtime client

import * as Drizzle from "alchemy/Drizzle/MySQL";

const conn = yield* Railway.ConnectMySQL(Db);
const db = yield* Drizzle.MySQL(conn.connectionString);

The application uses Railway’s private MySQL endpoint, not the public TCP proxy.

Query from the Service

import { Users } from "./schema.ts";

return {
  fetch: Effect.succeed(HttpServerResponse.text("Hello from Railway!")),
  fetch: Effect.gen(function* () {
    const users = yield* db.select().from(Users).pipe(Effect.orDie);
    return yield* HttpServerResponse.json({ users });
  }),
};

Use MySQL query semantics; PostgreSQL’s .returning() is not part of this example.

Deploy the application

pnpm alchemy deploy

For later changes, generate, review, and commit the schema, SQL, and snapshots before applying migrations and deploying compatible code. Railway.MySQL has no migrations prop, so alchemy deploy does not replace drizzle-kit migrate.

Continue

See the SQL database comparison, portable MySQL queries, and migration workflow. The MySQL database guide covers the resource’s image, volume, private hostname, and public proxy.