title: mysql type mismatch when inserting data into database using mysql-query
body: <p>I have this problem when I try to connect to my database using PHP and MySQL.it says:
  Fatal error: Uncaught TypeError: mysqli_query(): Argument #1 ($mysql) must be of type mysqli, string given in C:\xampp\htdocs\recruitment\seeker.joinus.register.php:14 Stack trace: #0 C:\xampp\htdocs\recruitment\seeker.joinus.register.php(14): mysqli_query('db_jobsportal', 'SELECT email_id...') #1 {main} thrown in C:\xampp\htdocs\recruitment\seeker.joinus.register.php on line 14
  require 'db.connect.php';</p>
  <pre><code>//Checking whether data already exist or not
  $flag = 0;
  $email_check = strtolower($_POST['user_email']);
  
  $query_select = &quot;SELECT email_id FROM seeker_details WHERE email_id='$email_check'&quot;;
  
  if($query_select_run = mysqli_query($con, $query_select))
  {
      $query_select_num = mysqli_num_rows($query_select_run);
      if($query_select_num == 0)
      {
          $flag = 1;
      }
      
      else if($query_select_num &gt;= 1)
      {
          echo '&lt;script&gt; alert(&quot;You had already joined with us. Send request to regain your password.&quot;); &lt;/script&gt;';
          echo '&lt;script&gt; window.location.href = &quot;seeker.forgot.passwprd.php&quot;; &lt;/script&gt;'; 
      }
  }
  </code></pre>