# MySQL (/docs/adapters/mysql)

Integrate Better Auth with MySQL.



MySQL is a popular open-source relational database management system (RDBMS) that is widely used for building web applications and other types of software. It provides a flexible and scalable database solution that allows for efficient storage and retrieval of data.
Read more here: [MySQL](https://www.mysql.com/).

## Example Usage [#example-usage]

Make sure you have MySQL installed and configured.
Then, you can connect it straight into Better Auth.

```ts title="auth.ts"
import { betterAuth } from "better-auth";
import { createPool } from "mysql2/promise";

export const auth = betterAuth({
  database: createPool({
    host: "localhost",
    user: "root",
    password: "password",
    database: "database",
    timezone: "Z", // Important to ensure consistent timezone values
  }),
});
```

<Callout>
  For more information, read Kysely's documentation to the
  [MySQLDialect](https://kysely-org.github.io/kysely-apidoc/classes/MysqlDialect.html).
</Callout>

<Callout type="warn">
  The Kysely adapter relies on the MySQL driver reporting "rows matched"
  semantics for `UPDATE` (mysql2 enables the `CLIENT_FOUND_ROWS` client flag
  by default — leave it on). If you opt out — for example by passing
  `flags: '-FOUND_ROWS'` to `createPool` — MySQL falls back to "rows changed"
  semantics. An idempotent `UPDATE` (new value equal to the current value)
  then reports zero affected rows, and `adapter.update`, `incrementOne`, and
  `updateMany` will treat that as a miss even though the predicate matched.
</Callout>

## Schema generation & migration [#schema-generation--migration]

The [Better Auth CLI](/docs/concepts/cli) allows you to generate or migrate
your database schema based on your Better Auth configuration and plugins.

<table>
  <thead>
    <tr className="border-b">
      <th>
        <p className="font-bold text-[16px] mb-1">
          MySQL Schema Generation
        </p>
      </th>

      <th>
        <p className="font-bold text-[16px] mb-1">
          MySQL Schema Migration
        </p>
      </th>
    </tr>
  </thead>

  <tbody>
    <tr className="h-10">
      <td>
        ✅ Supported
      </td>

      <td>
        ✅ Supported
      </td>
    </tr>
  </tbody>
</table>

<Tabs items="[&#x22;migrate&#x22;, &#x22;generate&#x22;]">
  <Tab value="migrate">
    <CodeBlockTabs defaultValue="npm" groupId="persist-install">
      <CodeBlockTabsList>
        <CodeBlockTabsTrigger value="npm">
          npm
        </CodeBlockTabsTrigger>

        <CodeBlockTabsTrigger value="pnpm">
          pnpm
        </CodeBlockTabsTrigger>

        <CodeBlockTabsTrigger value="yarn">
          yarn
        </CodeBlockTabsTrigger>

        <CodeBlockTabsTrigger value="bun">
          bun
        </CodeBlockTabsTrigger>
      </CodeBlockTabsList>

      <CodeBlockTab value="npm">
        ```bash
        npx auth@latest migrate
        ```
      </CodeBlockTab>

      <CodeBlockTab value="pnpm">
        ```bash
        pnpm dlx auth@latest migrate
        ```
      </CodeBlockTab>

      <CodeBlockTab value="yarn">
        ```bash
        yarn dlx auth@latest migrate
        ```
      </CodeBlockTab>

      <CodeBlockTab value="bun">
        ```bash
        bun x auth@latest migrate
        ```
      </CodeBlockTab>
    </CodeBlockTabs>
  </Tab>

  <Tab value="generate">
    <CodeBlockTabs defaultValue="npm" groupId="persist-install">
      <CodeBlockTabsList>
        <CodeBlockTabsTrigger value="npm">
          npm
        </CodeBlockTabsTrigger>

        <CodeBlockTabsTrigger value="pnpm">
          pnpm
        </CodeBlockTabsTrigger>

        <CodeBlockTabsTrigger value="yarn">
          yarn
        </CodeBlockTabsTrigger>

        <CodeBlockTabsTrigger value="bun">
          bun
        </CodeBlockTabsTrigger>
      </CodeBlockTabsList>

      <CodeBlockTab value="npm">
        ```bash
        npx auth@latest generate
        ```
      </CodeBlockTab>

      <CodeBlockTab value="pnpm">
        ```bash
        pnpm dlx auth@latest generate
        ```
      </CodeBlockTab>

      <CodeBlockTab value="yarn">
        ```bash
        yarn dlx auth@latest generate
        ```
      </CodeBlockTab>

      <CodeBlockTab value="bun">
        ```bash
        bun x auth@latest generate
        ```
      </CodeBlockTab>
    </CodeBlockTabs>
  </Tab>
</Tabs>

## Joins [#joins]

Database joins are useful when Better-Auth needs to fetch related data from multiple tables in a single query.
Endpoints like `/get-session`, `/get-full-organization` and many others benefit greatly from this feature,
seeing upwards of 2x to 3x performance improvements depending on database latency.

The Kysely MySQL dialect supports joins out of the box since version `1.4.0`.
To enable this feature, set `advanced.database.joins` to `true` in your auth configuration.

```ts title="auth.ts"
import { betterAuth } from "better-auth";

export const auth = betterAuth({
  advanced: {
    database: {
      joins: true,
    },
  },
});
```

## Additional Information [#additional-information]

MySQL is supported under the hood via the [Kysely](https://kysely.dev/) adapter, any database supported by Kysely would also be supported. (<Link href="/docs/adapters/other-relational-databases">Read more here</Link>)

If you're looking for performance improvements or tips, take a look at our guide to <Link href="/docs/guides/optimizing-for-performance">performance optimizations</Link>.