Iterating dropdown list with optgroup in PHP

Question

I am developing an application in CodeIgniter One of my dropdown consists of 86 options which should be generated dynamically and I have decided to make them in <optgroup> as shown in the below screenshot.

I have stored all these options in mysql database. Now my question is I want to iterate these options using foreach() loop so that the Group labels should display for each group. (In the screenshot Education, Hospitality). I don't like the way of hard coding these 86 options. Can someone help me in solving this problem.

Edit

This is my MySQL Table. I have mentioned Education list instead of occupation list. But the table structure is same.

mysql> select * from wededucationlist limit 10;
      +-------+---------------------------+
      | eduid | education                 |
      +-------+---------------------------+
      |     1 | Aeronautical Engineering  |
      |     2 | B Arch                    |
      |     3 | BCA                       |
      |     4 | BE/B-Tech                 |
      |     5 | B Plan                    |
      |     6 | BSc IT / Computer Science |
      |     7 | Other Bachelor Degree     |
      |     8 | M Arch                    |
      |     9 | MCA                       |
      |    10 | ME                        |
      +-------+---------------------------+
      10 rows in set (0.00 sec)

Answer 1

Even if the table you mentioned does not contain the data required, there is a very basic principle of achieving what you want to achieve:

• Query all Rows that should form the <options> and add a second column, beeing the <optgroup>.

like this:

Option 1 | Group 1
Option 2 | Group 1
Option 3 | Group 2
Option 4 | Group 3

• Iterate over all options, and whenever the group changes, print out an optgroup:

this one:

  <?php
    $data = array(array("option" => 1, "group" => "Group 1"),
       array("option" => 2, "group" => "Group 1"), 
       array("option"=>3, "group" => "Group 2"));

    $priorGroup = ""; 
    echo "<select>";
    foreach ($data AS $entry){
      if ($entry["group"] != $priorGroup){ //Start new optgroup if group changed.
         if ($priorGroup != ""){ //close prior optgroup if prior group WAS set.
           echo "</optgroup>"; 
         }

         echo "<optgroup label='{$entry["group"]}'>"; 
      }

      echo "<option>{$entry["option"]}</option>"; //show option(s)
      $priorGroup = $entry["group"]; //update priorGroup.
    }


    echo "</optgroup></select>"; //close last optgroup + select.
?>

Will output:

 Group 1
    1
    2
 Group 2
    3

Your database query need to sort by group (and optional by option afterwards) otherwhise you might get something like this:

 Group 1
    1
 Group 2
    3
 Group 1
    2

Answer 2

Optgroup with dynamic dropdown in codeigniter could be like this:

    //SANI: dropdown with optgroup   
    $result = $this->db->query("SELECT * FROM tbl_classes WHERE cls_id > '".$classId."'");
        $return = array('' => '-- Select Class -- ');
        if($result->num_rows() > 0) 
        {
            foreach($result->result_array() as $row) 
            {
                $resSec = $this->db->query("SELECT * FROM tbl_section WHERE sec_cls_id = '".$classId."'");
                if($resSec->num_rows() > 0) 
                {
                    foreach($resSec->result_array() as $sec)
                    { 
                        $return[$row['cls_name']][$sec['sec_id']] = $sec['sec_name'];
                    }
                }
            }
        }
        return $return;