I want to eliminate all the duplicates in a select dropdown list created with PHP.

My PHP code that creates the dropdown list is the following:

```
public static function getDropdownlist($conn)
{
    //Initialize dropdown list
    //--------------------------------------------------
    $ddl_query = "select * from MIS_EMPLOYEES";
    $stmt_ddl = oci_parse($conn, $ddl_query);
    oci_execute($stmt_ddl);
    //A default value -- this will be the selected item in the dropdown ##
    $prosopiko = JRequest::getVar('bodies', 0);
    if ($prosopiko == 0)
        $default = 0;
    else  
        $default = $prosopiko;
    //Initialize array to store dropdown options ##

      $options = array();
     // $options = array_unique();
      $options[] = JHTML::_('select.option', '0', 'Επιλέξτε');
      while (($row = oci_fetch_array($stmt_ddl, OCI_ASSOC+OCI_RETURN_NULLS)) != false) {
        $options[] = JHTML::_('select.option', $row['ID'], $row['POSITION']);
      }

    //Create <select name="month" class="inputbox"></select> ##
      $dropdown = JHTML::_('select.genericlist', $options, 'bodies', 'class="inputbox"', 'value', 'text', $default);

      return $dropdown; 
   }

}   

```

But it brings all the duplicates written from an Oracle table.

How can I eliminate the duplicates? I tried `array_unique` but I failed.