What is the significance of the error message "Query was empty" in PHP and how can it be resolved?

The error message "Query was empty" in PHP typically occurs when a SQL query string is empty or not properly constructed. This can happen when a variable containing the query is not being set or is being overwritten. To resolve this issue, ensure that the query string is properly constructed and not empty before executing it.

// Example of resolving "Query was empty" error in PHP
$query = "SELECT * FROM users WHERE id = 1";

if (!empty($query)) {
    // Execute the query
    $result = mysqli_query($connection, $query);
    // Rest of the code to handle the query result
} else {
    echo "Error: Query was empty";
}