php mysqli_result错误：给定布尔值（？）

Question

我收到此错误：

“警告：mysqli_num_rows（）要求参数1为mysqli_result，在（...）中给出布尔值”

并且不知道为什么......

这是我的代码：

（...）

$queryUser = "SELECT e_mail, tlm, p_nome, l_nome FROM USER WHERE e_mail= ".$e_mail." OR tlm= ".$tlm.";";
    
        
$result= mysqli_query($conn,$queryUser);
        
        if (!$result || mysqli_num_rows($result) == 0){
    
   $checkUser = mysqli_num_rows($result);
            }
    
    if($checkUser>0){
        
       $error= 'Utilizador já existe!';
      
 }else {
        
    if($pass ==  $pass2){
        
          $pass=md5($pass);
        
        
        try{
            
                $queryreg2= mysqli_query($conn,"INSERT INTO USER (id_user, e_mail, pass, p_nome, l_nome, tlm, admin, prof, ser, caminho,x,y,h,alt,xpos,ypos) VALUES('',".$e_mail.",".$pass.", ".$p_nome.", ".$l_nome.", ".$tlm.", '0','0','0','','0','0','0','','0','0');");
            
                 
    $queryIDUser = "SELECT id_user FROM USER WHERE e_mail= ".$e_mail." OR tlm= ".$tlm." AND p_nome= ".$p_nome." AND l_nome=".$l_nome.";";
     

$result2= mysqli_query($conn,$queryIDUser);
            
             if (!$result2 || mysqli_num_rows($result2) == 0){
    
   $get_id = mysqli_num_rows($result2);
    
    if($get_id==1){
        
    while($row = mysqli_fetch_array($result2)){
            
            $id_user=$row['id_user'];
        }
    

（...）

感谢您阅读我的SOS消息：）