What are the best practices for handling single-row results in PHP when using mysql_fetch_assoc?

When using mysql_fetch_assoc to retrieve results from a MySQL query in PHP, it is important to handle single-row results properly. One common mistake is to directly access the associative array returned by mysql_fetch_assoc without checking if there is actually a row to fetch. To handle single-row results, you should check if there is a row to fetch using mysql_num_rows, fetch the row using mysql_fetch_assoc, and then access the values from the associative array.

$result = mysql_query("SELECT * FROM table WHERE id = 1");
if(mysql_num_rows($result) == 1){
    $row = mysql_fetch_assoc($result);
    $value = $row['column_name'];
    // Do something with the value
} else {
    // Handle case where no row is found or multiple rows are returned
}