What are some potential causes for the error "Supplied argument is not a valid MySQL result" in PHP?

The error "Supplied argument is not a valid MySQL result" in PHP typically occurs when a query does not return a valid result set, often due to an issue with the query itself or the connection to the database. To solve this issue, you should check the query for errors, ensure the database connection is established correctly, and verify that the query is executed successfully.

// Example code snippet to fix the "Supplied argument is not a valid MySQL result" error
$query = "SELECT * FROM table_name";
$result = mysqli_query($connection, $query);

if($result) {
    // Process the result set
    while($row = mysqli_fetch_assoc($result)) {
        // Do something with the data
    }
} else {
    // Handle the error
    echo "Error: " . mysqli_error($connection);
}