MySQL Update Data

<?php

$sql="UPDATE table_name SET field1='value', field2='value2' WHERE id=1";
$result= mysql_query($sql);
echo "Data Updated Successfully";

?>

<?php

$sql="UPDATE students SET division='First' WHERE ROLL_NO=20";
// students is table name and division is field name
$result= mysql_query($sql);
echo "Data Updated Successfully";

?