php增删节查，自己写的demo

<?php
   //第一步：链接数据库
    $conn=@mysql_connect("localhost:3306","root","root")or die ("mysql链接失败");
  //第二步: 选择指定的数据库，设置字符集
    @mysql_select_db("php_blog",$conn) or die ("db链接失败".mysql_error());
	mysql_query('SET NAMES UTF8')or die ("字符集设置错误");

?>

<?php
  include("conn.php");//引入链接数据库
  if(!empty($_POST['sub'])){
	$title=$_POST['title'];
	$con=$_POST['con'];
	echo $sql="insert into news(id,title,dates,contents) value (null,'$title',now(),'$con')" ;
	mysql_query($sql);
	echo"插入成功";
  }
?>
<form action="add.php" method="post">
   标题: <input type="text" name="title"><br>
   内容: <textarea rows="5" cols="50" name="con"></textarea><br>
   <input type="submit" name="sub" value="发表">
</form>

<?php
  include("conn.php");//引入链接数据库<div class="code" style="position:relative; padding:0px; margin:0px;"><pre name="code" class="html"><?php
  include("conn.php");//引入链接数据库
  if(!empty ($_GET['id'])){
	 $sql="select * from news where id='".$_GET['id']."'";
	 $query=mysql_query($sql);
	 $rs=mysql_fetch_array($query);
	
  
  }

  if(!empty($_POST['sub'])){
	$title=$_POST['title'];
	$con=$_POST['con'];
	$hid=$_POST['hid'];
	$sql="update news set title='$title',contents='$con' where id='$hid' limit 1 ";

	mysql_query($sql);
	echo "<script> alert('更新成功'); location.href='index.php'</script>";
	echo"更新成功";
  }
?>
<form action="edit.php" method="post">
   <input type="hidden" name="hid" value="<?php echo $rs['id']?>"/>
   标题: <input type="text" name="title" value="<?php echo $rs['title']?>"><br>
   内容: <textarea rows="5" cols="50" name="con"><?php echo $rs['contents']?></textarea><br>
   <input type="submit" name="sub" value="发表">
</form>