Selection in Drop down list in wavemaker

Question

I m a beginner in wavemaker. Here I am using drop down list where I want to select option. Options are stored in a previously made database. Selection is done.But now I want that if I choose a option, then that option will be disabled for next dropdown. My page is like the given image.

PLease help. I want too store that options in a database also. need help for that also.
Codes:

<wm-tabcontent name="tabcontent1" horizontalalign="left">
                        <wm-composite name="composite2">
                            <wm-label class="col-xs-4" name="label3" width="200" height="25" caption="Battle field" fontweight="bold" textalign="center" fontsize="16" backgroundcolor="#8e8ee4"></wm-label>
                            <wm-container class="col-xs-8" name="container2" width="100">
                                <wm-select name="select2" width="100" dataset="bind:Variables.MyDTBSRankData.dataSet" datafield="rank" displayfield="rank"></wm-select>
                            </wm-container>
                        </wm-composite>
                        <wm-composite name="composite3">
                            <wm-label class="col-xs-4" name="label3" width="200" height="25" caption="Sprint-o-bot" fontweight="bold" textalign="center" fontsize="16" backgroundcolor="#8e8ee4"></wm-label>
                            <wm-container class="col-xs-8" name="container3" width="100">
                                <wm-select name="select3" width="100" dataset="bind:Variables.MyDTBSRankData.dataSet" datafield="rank" displayfield="rank"></wm-select>
                            </wm-container>
                        </wm-composite>
                        <wm-composite name="composite4">
                            <wm-label class="col-xs-4" name="label3" width="200" height="25" caption="Transporter" fontweight="bold" textalign="center" fontsize="16" backgroundcolor="#8e8ee4"></wm-label>
                            <wm-container class="col-xs-8" name="container4" width="100">
                                <wm-select name="select4" width="100" dataset="bind:Variables.MyDTBSRankData.dataSet" datafield="rank" displayfield="rank"></wm-select>
                            </wm-container>
                        </wm-composite>
                        <wm-composite name="composite5">
                            <wm-label class="col-xs-4" name="label3" width="200" height="25" caption="Robosoccer" fontweight="bold" textalign="center" fontsize="16" backgroundcolor="#8e8ee4"></wm-label>
                            <wm-container class="col-xs-8" name="container5" width="100">
                                <wm-select name="select5" width="100" dataset="bind:Variables.MyDTBSRankData.dataSet" datafield="rank" displayfield="rank"></wm-select>
                            </wm-container>
                        </wm-composite> 

Answer 1

To use database you have to use PHP like this :

echo '<select onchange="myFunction()">';
    print_option_list();
echo '</select>';

myfunction hide the option selected (the selected option must have the id="to_hide" )

myfunction() {
document.getElementById('to_hide').style.display = 'none';
}

print_option_list take the option's in your database like this :

function print_option_list() {
    //do the sql query that recupere your option's in a table
    //something like this 

          $query = "SELECT Options
                    FROM TableOptions
          $result=mysql_query($query);
          $tab=mysql_fetch_array($result);

    foreach( $options in $tab) {
        echo '<option value="' . $options . '"';
        echo '>' . $options . '</option>';
     }