What is the purpose of the database query in the PHP code provided?

The purpose of the database query in the PHP code provided is to retrieve data from a database table. To solve this issue, we need to ensure that the database connection is properly established and that the query is executed correctly to fetch the desired data.

// Establish a connection to the database
$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);
}

// Query to retrieve data from a table
$sql = "SELECT * FROM table_name";
$result = $conn->query($sql);

// Check if the query was successful
if ($result->num_rows > 0) {
    // Output data of each row
    while($row = $result->fetch_assoc()) {
        echo "Column1: " . $row["column1"]. " - Column2: " . $row["column2"]. "<br>";
    }
} else {
    echo "0 results";
}

// Close the database connection
$conn->close();