PHP form submission with check box, radio button and dropdown menu

1. For PHP checkbox form submission,  we still can only need one column in MySQL using PHP bitwise function &. (note we can have multi-choice in checkbox). Example code :
<input type="checkbox" name="competency[]" value="4" <?php if(($row['competency']&4) == 4){ echo('checked="checked"'); } ?>  />  Hard skill &nbsp;
<input type="checkbox" name="competency[]" value="2" <?php if(($row['competency']&2) == 2){ echo('checked="checked"'); } ?>  />  Soft skill &nbsp;
<input type="checkbox" name="competency[]" value="1" <?php if(($row['competency']&1) == 1){ echo('checked="checked"'); } ?>  />  Others
In the action side:
      $comp    =0;
     foreach($_POST['competency'] as $pc) {
      $comp = $comp + intval($pc);
     }
and insert $comp in database as column competency, which  will be used in $row['competency']

2. For dropdown menu:
 <select name="competency" id="competency">
     <option value="">- select  -</option>
     <option value="3" <?php if($row['competency'] == 3){ echo('selected="selected"'); } ?>  >  Hard skill </option>
     <option value="2" <?php if($row['competency'] == 2){ echo('selected="selected"'); } ?>  > Soft skill </option>
     <option value="1" <?php if($row['competency'] == 1){ echo('selected="selected"'); } ?>  > Others </option>
     </select>
In the action side:, we can insert $_POST['competency'] as it is a unique  value.


3. For radio button:
    <input type="radio" id="c1" class="input-radio" name="competency" value="3" <?php if($row['competency'] == 3){ echo('checked="checked"'); } ?>  />
   <label for="c1">Yes, with hard skill</label>
  
   <input type="radio" id="c2" class="input-radio" name="competency" value="2" <?php if($row['competency'] == 2){ echo('checked="checked"'); } ?>  />
   <label for="c2">Yes, with soft skill</label>
 
   <input type="radio" id="c3" class="input-radio" name="competency" value="1" <?php if($row['competency'] == 1){ echo('checked="checked"'); } ?>  />
   <label for="c3">No</label> <br />
In the action side:, we can insert $_POST['competency'] as it is a unique  value.