表单验证检查输入的位数

Question

这是我将数据插入数据库的 PHP 文件。
我需要验证输入的pmob_number 是否小于 10 位，然后再将其存储到数据库中。

<?php 
 $servername = "localhost";  
       $username = "root";  
       $password = "";  
       $conn = mysqli_connect ($servername , $username , $password) or  die("unable to connect to host");  
       $sql = mysqli_select_db ($conn,'vcet') or die("unable to connect to  database"); 




 //code to insert into db...
 $user_name=$_POST['user_name']; 
 $roll_number=$_POST['roll_number'];
 $user_batch=$_POST['user_batch'];
 $user_from=$_POST['user_from'];
 $user_year=$_POST['user_year'];
 $user_level=$_POST['user_level'];
 $F_name=$_POST['F_name'];
 $m_name=$_POST['m_name'];
 $g_name=$_POST['g_name'];
 $mob_number=$_POST['mob_number'];
 $addressline1=$_POST['addressline1'];
 $addressline2=$_POST['addressline2'];
 $city=$_POST['city'];
 $pmob_number=$_POST['pmob_number'];


    $msg="";

    $number_valid=$_POST['pmob_number'];

    if(strlen($number_valid)!=10){
        $msg='<span class="error">The number you enteres was not 10 digit    long</span>';

    }else
    {
        echo"valid";
    }



 $land_number=$_POST['land_number'];
 $cutoff=$_POST['cutoff'];
 $dept=$_POST['dept'];
 $medium = $_POST['medium'];
 $locality=$_POST['locality'];
 $intrest=$_POST['intrest'];
 $scholar=$_POST['scholar'];
 $income=$_POST['income'];
 $user_caste=$_POST['user_caste'];
 $user_admit=$_POST['user_admit'];
 $user_stay=$_POST['user_stay'];







 $user_info = "INSERT INTO studentinfo"." (user_name,roll_number,user_batch,user_from,user_year,user_level,F_name,m_name,g _name,mob_number,addressline1,addressline2,city,pmob_number,land_number,cutoff,d ept,medium,locality,intrest,scholar,income,user_caste,user_admit, user_stay)". "VALUES ('$user_name', '$roll_number','$user_batch','$user_from','$user_year','$user_level','$F_name','$m_name','$g_name','$mob_number','$addressline1','$addressline2','$city','$pmob_number','$land_number','$cutoff','$dept','$medium','$locality','$intrest','$scholar','$income','$user_caste','$user_admit','$user_stay')"; 
 if (!mysqli_query($conn,$user_info)) { die('Error: ' .  mysqli_error($conn)); } echo "Your information was added to the database."; 
 mysqli_close($conn); 
 ?>

Answer 1

您可以使用strlen() 进行服务器端验证

编辑：这一定能解决问题

$num_length = strlen((string)$pmob_number);
if($num_length == 10) {

     $user_info = "INSERT INTO studentinfo"." (user_name,roll_number,user_batch,user_from,user_year,user_level,F_name,m_name,g _name,mob_number,addressline1,addressline2,city,pmob_number,land_number,cutoff,d ept,medium,locality,intrest,scholar,income,user_caste,user_admit, user_stay)". "VALUES ('$user_name', '$roll_number','$user_batch','$user_from','$user_year','$user_level','$F_name','$m_name','$g_name','$mob_number','$addressline1','$addressline2','$city','$pmob_number','$land_number','$cutoff','$dept','$medium','$locality','$intrest','$scholar','$income','$user_caste','$user_admit','$user_stay')"; 
     if (!mysqli_query($conn,$user_info)) { 
        die('Error: ' .  mysqli_error($conn));
     }

     echo "Your information was added to the database."; 

    mysqli_close($conn); 

} else {
    $msg='<span class="error">The number you enteres was not 10 digit    long</span>';

}