MySQL

MySQL setup with the Kysely adapter, connection configuration, and compatibility notes.

MySQL is supported through the Kysely adapter with provider: "mysql". Use mysql2 for the connection pool.

Installation

pnpm add @better-media/adapter-db-kysely kysely mysql2

Configuration

import { createPool } from "mysql2/promise";
import { Kysely, MysqlDialect } from "kysely";
import { KyselyDbAdapter } from "@better-media/adapter-db-kysely";
import { schema } from "@better-media/core";

const pool = createPool({
  host: process.env.MYSQL_HOST ?? "localhost",
  port: Number(process.env.MYSQL_PORT ?? 3306),
  database: process.env.MYSQL_DATABASE,
  user: process.env.MYSQL_USER,
  password: process.env.MYSQL_PASSWORD,
  connectionLimit: 10,
  ssl: process.env.NODE_ENV === "production" ? { rejectUnauthorized: true } : undefined,
});

const db = new Kysely({ dialect: new MysqlDialect({ pool }) });

const database = new KyselyDbAdapter(db, {
  config: { provider: "mysql" },
  schema,
});

const media = createBetterMedia({ storage, database, plugins });

Migrations

# Preview generated SQL
npx better-media generate --dialect mysql

# Apply migrations
npx better-media migrate --yes

Or programmatically on startup:

import { runMigrations } from "@better-media/core";
await runMigrations(database, schema);

Connection Strings

# Local development
MYSQL_HOST=localhost
MYSQL_PORT=3306
MYSQL_DATABASE=mydb
MYSQL_USER=root
MYSQL_PASSWORD=secret

# PlanetScale / hosted MySQL (SSL required)
DATABASE_URL=mysql://user:pass@host/dbname?ssl={"rejectUnauthorized":true}

Compatibility Notes

No RETURNING clause. MySQL does not support INSERT ... RETURNING. Better Media handles this transparently.

JSON columns. The metadata, errors, threats, result, and other json-typed fields in the schema are stored as MySQL JSON columns (MySQL 5.7.8+). Ensure your MySQL version supports native JSON.

Character set. Use utf8mb4 for your database and tables to avoid encoding issues with filenames that contain non-ASCII characters:

CREATE DATABASE mydb CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

The CLI migration generates tables without an explicit charset — set it at the database level so all tables inherit it.

PlanetScale. PlanetScale disables foreign key constraints by default. Better Media's schema defines foreign keys (e.g. mediaId references media.id), but the adapter will still function correctly because constraint enforcement happens at the application layer. Cascade deletes will not fire automatically — use database.deleteMany() explicitly.