<a href ='index.php' >返回留言板</a><hr><hr><?php/* * To change the template for this generated file go to * Window - Preferences - PHPeclipse - PHP - Code Templates */require("conn.php"); $user=$_POST['user']; $title=$_POST['title'];$content=$_POST['content'];$sql_luck="insert into sny (id,user,title,content,lastDate)value('','$user','$title','$content',now())"; $sql="SELECT user FROM sny WHERE user='$user'"; $query =mysql_query($sql); $rows=mysql_fetch_array($query);if((!empty($_POST['sub']))and($rows['user']==$user)){//echo $content; echo "<script>alert('用户已存在,请重新输入');location.href='add2.php'</script>" ;exit; mysql_free_result($query);exit; } else{ mysql_query($sql_luck); echo"<script>alert('哟!成功!');location.href='index.php'</script>"; echo "插入成功"; } ?><form action="add.php" method="post">用户:<input type="text" name="user" value="请输入用户名" size="20" maxlength="10"/><br/>标题:<input type="text" name="title" value="请输入内容" size="40" maxlength="40"/><br/>内容:<textarea name="content" rows="10" cols="50" wrap="off">text</textarea> <br/> <input type="submit" name="sub" value="Release"/><br/> <form/>
2、对自增字段赋空字符,出错的概率50%