The following is the updated `compose.yaml` file. All comments have been removed.

```yaml
services:
  server:
    build:
      context: .
    ports:
      - 9000:80
    depends_on:
      db:
        condition: service_healthy
    secrets:
      - db-password
    environment:
      - PASSWORD_FILE_PATH=/run/secrets/db-password
      - DB_HOST=db
      - DB_NAME=example
      - DB_USER=root
  db:
    image: mariadb
    restart: always
    user: root
    secrets:
      - db-password
    volumes:
      - db-data:/var/lib/mysql
    environment:
      - MARIADB_ROOT_PASSWORD_FILE=/run/secrets/db-password
      - MARIADB_DATABASE=example
    expose:
      - 3306
    healthcheck:
      test:
        [
          "CMD",
          "/usr/local/bin/healthcheck.sh",
          "--su-mysql",
          "--connect",
          "--innodb_initialized",
        ]
      interval: 10s
      timeout: 5s
      retries: 5
volumes:
  db-data:
secrets:
  db-password:
    file: db/password.txt
```

> [!NOTE]
>
> To learn more about the instructions in the Compose file, see [Compose file
> reference](/reference/compose-file/).

Before you run the application using Compose, notice that this Compose file uses
`secrets` and specifies a `password.txt` file to hold the database's password.
You must create this file as it's not included in the source repository.

In the `docker-php-sample` directory, create a new directory named `db` and
inside that directory create a file named `password.txt`. Open `password.txt` in an IDE or text editor and add the following password. The password must be on a single line, with no additional lines in the file.

```text
example
```

Save and close the `password.txt` file.

You should now have the following in your `docker-php-sample` directory.

```text
├── docker-php-sample/
│ ├── .git/
│ ├── db/
│ │ └── password.txt
│ ├── src/
│ ├── tests/
│ ├── .dockerignore
│ ├── .gitignore
│ ├── compose.yaml
│ ├── composer.json
│ ├── composer.lock
│ ├── Dockerfile
│ ├── README.Docker.md
│ └── README.md
```

Run the following command to start your application.

```console
$ docker compose up --build
```

Open a browser and view the application at [http://localhost:9000/database.php](http://localhost:9000/database.php). You should see a simple web application with text and a counter that increments every time you refresh.

Press `ctrl+c` in the terminal to stop your application.

## Verify that data persists in the database

In the terminal, run `docker compose rm` to remove your containers and then run `docker compose up` to run your application again.

```console
$ docker compose rm
$ docker compose up --build
```

Refresh [http://localhost:9000/database.php](http://localhost:9000/database.php) in your browser and verify that the previous count still exists. Without a volume, the database data wouldn't persist after you remove the container.

Press `ctrl+c` in the terminal to stop your application.

## Add phpMyAdmin to interact with the database

You can easily add services to your application stack by updating the `compose.yaml` file.

Update your `compose.yaml` to add a new service for phpMyAdmin. For more details, see the [phpMyAdmin Official Docker Image](https://hub.docker.com/_/phpmyadmin). The following is the updated `compose.yaml` file.

```yaml {hl_lines="42-49"}
services:
  server:
    build:
      context: .
    ports:
      - 9000:80
    depends_on:
      db:
        condition: service_healthy
    secrets:
      - db-password
    environment:
      - PASSWORD_FILE_PATH=/run/secrets/db-password
      - DB_HOST=db
      - DB_NAME=example
      - DB_USER=root
  db:
    image: mariadb
    restart: always
    user: root
    secrets:
      - db-password
    volumes:
      - db-data:/var/lib/mysql
    environment:
      - MARIADB_ROOT_PASSWORD_FILE=/run/secrets/db-password
      - MARIADB_DATABASE=example
    expose:
      - 3306
    healthcheck:
      test:
        [
          "CMD",
          "/usr/local/bin/healthcheck.sh",
          "--su-mysql",