<?php
header("Content-type: text/html; charset=utf-8");
$conn =mysqli_connect("localhost","root","");
if (!$conn){
   echo "<script>alert('连接失败！');history.go(-1);</script>";
  } 
mysqli_select_db($conn,"liuyanban");
mysqli_query($conn,'SET NAMES utf8');
$password=$_POST['password'];
$username=$_POST['username'];
$face="yellow.png";
$result=mysqli_query($conn,"SELECT username from user1 where username = '$username'"); 
$a=mysqli_num_rows($result);
if($a)
{    
   echo "<script language=javascript>alert('用户名已存在！');location.href='reg.html'</script>";
}
else
{   
    $sql = mysqli_query($conn,"INSERT INTO user1(username,password,face)VALUES('1' ,'2','yellow.png')");
   if($sql)
   {
      echo "<script language=javascript>alert('注册成功!');location.href='login.html'</script>";
   }
   else
   {
      echo "<script>alert('注册失败！');location.href='reg.html'</script>";
   }
}
?>

public function doreg(){
       $data=D('user');
       $d=array();
         $d['username']=$_POST['username'];
         $d['password']=$_POST['password'];
         $d['time']=date("Y-m-d H:i:s",time());
         $d['qq']=$_POST['qq'];
         $d['class']=$_POST['class'];
         $mess=$data->create();
         if (!$mess){    //表单自动验证
            $this->error($data->getError(),'Member/member',3);
         }else{
            $data->add();
            echo "<script language=javascript>alert('注册成功!');location.href='member.html'</script>";
           }
         }

<?php 
namespace Home\Model;
use Think\Model;
  class UserModel extends Model{
    protected $tableName ='user';   
    protected $_validate=array(                 //进行静态验证
     //array(验证字段1,验证规则,错误提示,[验证条件,附加规则,验证时间]),
      array('username','require','用户名必填！'),
      array('username','','帐号名称已经存在！',0,'unique',1),
      array('repassword','password','两次密码不一致！',0,'confirm'),
      array('qq','require','qq必填！'),
      array('qq','','帐号名称已经存在！',0,'unique',1),
      array('class','require','班级必填！'),
      array('j_verify','require','验证码必须！'),
    );
     
  }
?>