虽然登录时我正在尝试验证3个表中的值，但是不起作用？ [重复]

Question

此问题已经在这里有了答案：

Can I mix MySQL APIs in PHP?（4个答案）

关闭4年前。

我遇到这些错误：

警告：mysql_query（）期望参数1是字符串，第12行的H：\ xamp \ htdocs \ newlogintry.php中给出的对象

警告：mysql_query（）期望参数1为字符串，在第13行的H：\ xamp \ htdocs \ newlogintry.php中给出的对象

警告：mysqli_num_rows（）期望参数1为mysqli_result，第18行的H：\ xamp \ htdocs \ newlogintry.php中给定的null

但是这是我为此编写的php代码，我想检查帐户的“类型”是教师帐户还是学生帐户（如果其中有的话），然后使用各自的类型参数传递到主页，请告诉如果我对php的用法是正确的，因为我对它不熟悉，这是php代码（newlogintry.php）

<?php
$start=1;
$username=$_GET['username'];
$password=$_GET['password'];

$con=mysqli_connect("localhost","root","","repute system");
    if(mysqli_connect_errno()){
        echo "ERROR ".mysqli_connect_error();
    } 
        //$result = mysqli_query($con,"SELECT password FROM accounts WHERE username=".$username);
    $result = mysqli_query($con,"SELECT password,username,type,u_name FROM accounts ");
    $new = mysql_query($con, "SELECT name,USN,repute,acc_type,u_name FROM pupil ");
    $new1= mysql_query($con,"SELECT name,id,repute,acc_type,u_name FROM teacher");    




      if(mysqli_num_rows($new)>0)
        {
         while($row = mysqli_fetch_assoc($new)) {

                $pupilaccount = $row['acc_type'];       


                if(mysqli_num_rows($new1)>0)
                 {
                       while($row = mysqli_fetch_assoc($new1)) {
                           $teacheraccount = $row['acc_type'];


                            if(mysqli_num_rows($result)>0)
                             {
                                  while($row = mysqli_fetch_assoc($result)) {


                                        $pass=$row['password'];
                                        $use=$row['username'];
                                        $type=$row['type'];

                                        if( $type==$teacheraccount and $password == $pass and $username==$use){
                                                 header("location:http://localhost/index.php?param=$teacheraccount&param1=$username");  
                                          exit();
                                      }
                                      else if($type==$pupilaccount and $password == $pass and $username==$use)
                                      {
                                            header("location:http://localhost/index.php?param==$pupilaccount&param1=$username");   
                                            exit();   
                                      }
                                  }
                            }         
             }
        }
      }              



        }
      }




?>

Answer 1

错误消息：