提交后，在选择框中显示多个项目

To get the chosen value in a select box after submit. I use:

<option value="<?=$row["status"]?>" <?=($row["status"]==$status) ? 'selected' : ''?> >

How do I get multiple items when using an array in PHP?

                <div class="row">
                    <div class="col-md-3" style="padding-top:5px">Status</div>
                    <div class="col-md-6" style="padding-top:5px">
                        <select name="status[]" class="form-control selectpicker" multiple>
                            <?php
                            $sel = "
                                SELECT DISTINCT
                                    t.status,
                                    s.*
                                FROM tickets t
                                LEFT JOIN statussen s
                                ON t.status = s.stid
                                GROUP BY s.stid
                                ";
                            $selres = mysqli_query( $link, $sel );
                            while ( $row = mysqli_fetch_array( $selres ) ):
                                ?>
                            <option value="<?=$row["status"]?>" <?=($row["status"]==$status) ? 'selected' : ''?> >
                                <?=$row["status_omschr"]?>
                            </option>
                            <?php endwhile; ?>
                        </select>
                    </div>

Try the following:

1. Add before your loop:

   $selectedItems = [];
   if(isset($_POST['status'])) {
     $selectedItems = $_POST['status'];
   }
   

2. Change within the loop:

   <option value="<?=$row["status"]?>" <?=(in_array($row["status"], $_POST['status'])) ? 'selected' : ''?> >
     <?=$row["status_omschr"]?>
   </option>
   

You can do it with using in_array() function in condition like below.

 <option value="<?=$row["status"]?>" <?php if(isset($_POST['status']) and !empty($_POST['status'])){ ?> <?=(in_array($row["status"], $_POST['status'])) ? 'selected' : ''?> <?php }?>  >
  <?=$row["status_omschr"]?>
</option>