How can JOIN statements be incorporated into SQL queries in PHP to retrieve related data?

To retrieve related data from multiple tables in a database, JOIN statements can be incorporated into SQL queries in PHP. By using JOIN statements, you can specify how the tables are related and retrieve data from multiple tables based on those relationships. Example PHP code snippet incorporating JOIN statements: 

<?php
// Establish a database connection
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "database";

$conn = new mysqli($servername, $username, $password, $dbname);

// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}

// SQL query with JOIN statement to retrieve related data
$sql = "SELECT users.username, orders.order_id FROM users JOIN orders ON users.user_id = orders.user_id";

$result = $conn->query($sql);

if ($result->num_rows > 0) {
    // Output data of each row
    while($row = $result->fetch_assoc()) {
        echo "Username: " . $row["username"]. " - Order ID: " . $row["order_id"]. "<br>";
    }
} else {
    echo "0 results";
}

$conn->close();
?>

Keywords

JOIN SQL queries PHP related data data retrieval

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