yii框架，增删改查，sql
1.$sql= "insert into tbl_user(`id`,`username`,`password`)values(null,'alu','123');
2.$sql= "select * from tbl_user where id=1;
3.$sql= "update tbl_user set password="123456" where id=6";
4.$sql= "delete from tbl_user where id=6;";
//设置字符编码
mysql_query("set names utf8");
$result=mysql_query($sql) or die('sql语句错误，系统给的提示是:'.mysql_error());
5.$num = mysql_num_rows($result)以及$num=mysql_fetch_array($result);
以上语句在yii框架里面应该怎样写？[/color][/color]
