What common errors can occur when using the mysql_fetch_assoc function in PHP?

One common error that can occur when using the mysql_fetch_assoc function in PHP is trying to fetch data from a result set that has already been completely fetched. This can result in returning false or an empty array. To avoid this error, you should always check if there are more rows to fetch before calling mysql_fetch_assoc.

// Check if there are more rows to fetch before calling mysql_fetch_assoc
while ($row = mysql_fetch_assoc($result)) {
    // Process the fetched row here
}