What is the significance of the error message "mysql_fetch_assoc() expects 1 to be resource, string given" in PHP and how can it be resolved?

The error message "mysql_fetch_assoc() expects 1 to be resource, string given" in PHP indicates that the function is expecting a resource type (result set) from a MySQL query, but it's receiving a string instead. This usually happens when the query execution fails, and the result is not a valid resource. To resolve this issue, you need to check if the query execution was successful before trying to fetch the results.

// Check if the query execution was successful before fetching results
$result = mysqli_query($connection, $query);
if($result) {
    while($row = mysqli_fetch_assoc($result)) {
        // Process the fetched data
    }
} else {
    echo "Error: " . mysqli_error($connection);
}