通过php从mysql数据库中检索行时没有错误但无法正常工作

Question

这是用于从mysql数据库检索查询的php代码。据我所知，这没有错误。不幸的是，这不起作用。我找不到错误。

        <?php 

                    if(isset($_POST['submit']))    // submit is submit button name as POST method
                    {               
                        $username = $_POST['in'];
                        $Timein= date("Y-m-d H:i:s",strtotime(str_replace('/','-',$username)));  // converting into mysql datetime format
                        $username = $_POST['out'];
                        $Timeout = date("Y-m-d H:i:s",strtotime(str_replace('/','-',$username)));



                        $dbc = mysqli_connect('localhost','dev','dev@123','Database') or die('Error while connecting Database'.mysql_connect_error); 

                        // connection to database

                    $q="select * from camera where NOT chkin  > '$Timein' AND NOT chkout < '$Timeout'";
                    $r = mysqli_query($dbc,$q);                             

                    // query 
                    while ($data = mysqli_fetch_assoc($r)){ ?>

                        // printing a bootstrap grid 
                        <div class="col-lg-3 col-md-3 col-sm-6 col-xs-6 col-xxs-12">
                            <div class="tm-tours-box-2">                        
                                <img src="img/index-0 <?php echo $data['id'];?>.jpg" alt="image" class="img-responsive">
                                <div class="tm-tours-box-2-info">
                                    <h3 class="margin-bottom-15"><?php echo $data['name']; ?></h3>
                                    <p>Rs <?php echo $data['price']; ?>/day</p> 
                                </div>                      
                                <a  class="tm-tours-box-2-link" onclick="POP()">Book Now</a>
                            </div>
                        </div>


                    <?php                                       

                    }   
                     }
        ?>