> For the complete documentation index, see [llms.txt](https://dhrubo.gitbook.io/programming-with-js/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://dhrubo.gitbook.io/programming-with-js/php/integrating-php-with-mysql-database.md).

# Integrating PHP with MySQL database

Here's an overview of integrating PHP with MySQL database:

1. Connecting to the database: Before working with a MySQL database, you need to establish a connection to it. This is typically done using the `mysqli_connect()` function. Here's an example:

   ```php
   $host = "localhost"; // The database server host
   $user = "username"; // The database username
   $password = "password"; // The database password
   $database = "mydatabase"; // The name of the database to connect to

   $conn = mysqli_connect($host, $user, $password, $database);

   if (!$conn) {
       die("Connection failed: " . mysqli_connect_error());
   }
   ```

   In this example, we're connecting to a MySQL database on the local server using the username and password specified. If the connection fails, an error message is displayed.
2. Executing SQL queries: Once you have established a connection to the database, you can execute SQL queries using the `mysqli_query()` function. Here's an example:

   ```php
   $sql = "SELECT * FROM users";
   $result = mysqli_query($conn, $sql);

   if (mysqli_num_rows($result) > 0) {
       while ($row = mysqli_fetch_assoc($result)) {
           echo "ID: " . $row["id"] . " - Name: " . $row["name"] . "<br>";
       }
   } else {
       echo "0 results";
   }
   ```

   In this example, we're executing a `SELECT` query to retrieve all rows from the `users` table. We're then using a `while` loop to iterate over the rows and display the `id` and `name` fields for each row.
3. Closing the connection: When you're finished working with the database, it's a good practice to close the connection using the `mysqli_close()` function. Here's an example:

   ```php
   mysqli_close($conn);
   ```

   This will close the connection to the database.

Overall, integrating PHP with MySQL involves establishing a connection to the database, executing SQL queries, and closing the connection when finished.

Here's a complete example that demonstrates the above concepts:

```php
<?php
$host = "localhost";
$user = "username";
$password = "password";
$database = "mydatabase";

$conn = mysqli_connect($host, $user, $password, $database);

if (!$conn) {
    die("Connection failed: " . mysqli_connect_error());
}

$sql = "SELECT * FROM users";
$result = mysqli_query($conn, $sql);

if (mysqli_num_rows($result) > 0) {
    while ($row = mysqli_fetch_assoc($result)) {
        echo "ID: " . $row["id"] . " - Name: " . $row["name"] . "<br>";
    }
} else {
    echo "0 results";
}

mysqli_close($conn);
?>
```

This code connects to a MySQL database, executes a `SELECT` query to retrieve all rows from the `users` table, and displays the `id` and `name` fields for each row.