php，sql语句如何调用参数？

Question

 $result=mysql_query("select * from product_sort where fathersid='"$row['serial']"' order by orderindex,serial desc");
上面这样写是出错的，我想查询fathersid=$row['serial']的值，请问高手们如何写？菜鸟在这里感谢了！

Answer 1

"select * from product_sort where fathersid='" . $row['serial'] . "' order by orderindex,serial desc"

Answer 2

 $result=mysql_query("select * from product_sort where fathersid='".$row['serial']."' order by orderindex,serial desc");

Answer 3

 $result=mysql_query("select * from product_sort where fathersid='" .$row['serial']. "' order by orderindex,serial desc");
或
 $result=mysql_query("select * from product_sort where fathersid='{$row['serial']}' order by orderindex,serial desc");
或
 $result=mysql_query("select * from product_sort where fathersid='$row[serial]' order by orderindex,serial desc");