php - Submiting form within model not saving data to database -

i trying simple save of data database. have form in modal.

when try save data database, not save. if place form out of modal save data database.

i have googled solution found none. submit button in form, thats not causing issue.

php code:

<?php ini_set('display_errors', 'on');    error_reporting(e_all | e_strict);   session_start(); include 'config.php';  if(!isset($_session['user_id'])) {     header("location: login.php"); }  //read out data db $query_string = "select * tbl_category"; $query = mysqli_query($con, $query_string);  //save data db if(isset($_post['savecategory'])){   $category = mysqli_real_escape_string($con, $_post['category']);   $query = "insert tbl_category(category) values('$category')";    $result = mysqli_query($con, $query);    if(!$result){       echo mysqli_error();   }   else{     $category = '';     echo "yes";   } }  ?> 

my config.php file:

<?php $con = mysqli_connect("localhost", "root", "root", "challenger") or die("error " . mysqli_error($con));  // if($con){ //          echo"there connection"; //   }  ?> 

part of html code:

 <!-- page content -->  <div id="page-wrapper">     <div class="container-fluid">       <div class="row bg-title">         <div class="col-lg-3 col-md-4 col-sm-4 col-xs-12">           <h4 class="page-title">category</h4>         </div>         <div class="col-lg-9 col-sm-8 col-md-8 col-xs-12">           <ol class="breadcrumb">             <li><a href="#">category</a></li>             <li><a href="#" class="active">category</a></li>           </ol>         </div>         <!-- /.col-lg-12 -->       </div>       <!-- /row -->       <div class="row">         <div class="col-sm-12">           <div class="white-box">             <h3 class="box-title m-b-0">overview category</h3>             <button class="btn btn-danger btn-outline pull-right" data-toggle="modal" data-target="#addcategory">add category</button>             <br><br><br>             <table id="mytable" class="table table-striped">               <thead>                 <tr>                   <th>number</th>                   <th>category</th>                 </tr>               </thead>               <tbody>                 <?php                   while($row = mysqli_fetch_assoc($query)){                     echo "<tr>";                       echo "<td>".$row['category_id']."</td>";                       echo "<td>".$row['category']."</td>";                     echo "</tr>";                     }                     ?>               </tbody>             </table>           </div>         </div>              <!-- modal window -->             <div class="modal fade" id="addcategory" tabindex="-1" role="dialog" aria-labelledby="examplemodallabel1">               <div class="modal-dialog" role="document">                 <div class="modal-content">                   <div class="modal-header">                     <button type="button" class="close" data-dismiss="modal" aria-label="close"><span aria-hidden="true">&times;</span></button>                     <h4 class="modal-title" id="examplemodallabel1">add new category</h4>                   </div>                   <div class="modal-body">                     <form action="<?php echo $_server['php_self']; ?>" method="post">                       <div class="form-group">                         <label for="recipient-name" class="control-label">category name:</label>                         <input type="text" class="form-control" id="recipient-name1" name="category">                       </div>                       <div class="modal-footer">                         <button type="button" class="btn btn-default" data-dismiss="modal">close</button>                         <button type="submit" class="btn btn-primary" name="savecategory" data-dismiss="modal">create category</button>                       </div>                     </form>                   </div><!-- end modal body -->                 </div>               </div>             </div>             <!-- end modal window -->        </div>       <!-- /.row -->     </div>     <!-- /.container-fluid -->   </div>   <!-- /end page content --> 

change

  $query = "insert tbl_category(category) values('$category')";  

to this

  $query = "insert tbl_category(`category`) values('$category')";