What potential issue is the user facing with the "No Database selected" error in their PHP scripts?

The "No Database selected" error in PHP scripts typically occurs when the script attempts to interact with a database without specifying which database to use. To solve this issue, you need to ensure that you have selected the appropriate database using the mysqli_select_db function before executing any queries.

// Connect to MySQL database
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "database_name";

$conn = mysqli_connect($servername, $username, $password, $dbname);

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

// Select the database
mysqli_select_db($conn, $dbname);