php怎么操作数据库

//链接数据库
$db=mysql_connect("localhost", "root","123456");
$sqlname="database";
mysql_select_db($sqlname,$db);
session_start();
mysql_query("SET NAMES 'utf8'",$db);
?>

<?
//创建结果集
$sql = "SELECT * FROM kecheng";
$result = mysql_query($sql); 
$rs= mysql_fetch_array($result);
?>

<?
//修改数据
$sql = "UPDATE news SET  title='1111'   where news_id=1";
$result = mysql_query($sql);
?>

<?
//删除数据
$sql = "DELETE from news  where news_id=1";
$result = mysql_query($sql);
?>

<?
//添加数据
$sql = "INSERT INTO news (title,fenshu) VALUES ('a',1)"
$result = mysql_query($sql);
?>