Creating foreach loops using Code Igniter controll

问题:

This is a situation I have found myself in a few times and I just want clear it up once and for all.

Best just to show you what I need to do in some example code.

My Controller

function my_controller()
{

$id = $this->uri->segment(3);

$this->db->from('cue_sheets');
$this->db->where('id', $id);
$data['get_cue_sheets'] = $this->db->get();

$this->db->from('clips');
$this->db->where('sheet_id', ' CUE SHEET ID GOES IN HERE ??? ');
$data['get_clips'] = $this->db->get();

$this->load->view('show_sheets_and_clips', $data);

}

My View

<?php if($get_cue_sheets->result_array()) { ?>
    <?php foreach($get_cue_sheets->result_array() as $sheetRow): ?>
        <h1><?php echo $sheetRow['sheet_name']; ?></h1>
        <br/>
        <?php if($get_clips->result_array()) { ?>
            <ul>
                <?php foreach($get_clips->result_array() as $clipRow): ?>
                    <li><?php echo $clipRow['clip_name']; ?></li>
                <?php endforeach; ?>
            </ul>
        <?php } else { echo 'No Clips Found'; } ?>
    <?php endforeach; ?>
<?php } ?>

So basically I am trying to display a number of sheets and then within each of those sheets the clips that belong to that sheet.

I hope this makes sense to someone out there.

Thanks,

Tim

回答1:

A user on the Code Igniter Forums came up with the solution below. The original thread is here.

It’s not efficient to look up the clips for every sheet separately. Use a JOIN query to get both lists at the same time.

// get the data
$this->db->from('cue_sheets');
$this->db->where('cue_sheets.id', $id);
$this->db->join('clips', 'clips.sheet_id = cue_sheets.id', 'left');
$rawdata = $this->db->get()->result_array();
// prepare the data into a multidimensional array
$data = array();
foreach($rawdata as $row)
{
  // if this is the first clip of a new sheet, make a new entry for it
  if (!isset($data[$row['id']]))
  {
    $data[$row['id']] = $row;
    $data[$row['id']]['clips'] = array();
  }  

  // add the current clip to the sheet
  $data[$row['id']]['clips'][] = $row;
}

Now in your view you can loop through the sheets, and within that, loop through the clips:

foreach($data as $sheet) {
  // make header etc.
  if (sizeof($sheet['clips']))
  {
    foreach($sheet['clips'] as $clip)
    {
      // show clip
    }
  } else {
    // show 'no clips'
  }
} 

Thanks again,

Tim

回答2:

You should do a join in your model for both tables, and create one result which you will move later to your view trough the controller.

Remember not to put queries in your controller.

maybe somthing like this:

function get_data($cue_sheets){
$this->db->select(clips.*);
$this->db->from('clips');
$this->db->join('cue_sheets', 'clips.idcuesheet = cue_sheets.idcuesheet' );
$this->db->where('cue_sheets.idcuesheet', $cue_sheets);
$query = $this->db->get();
}

Or something similar.

Then you bring it to the controller

$data['clips'] = $this->clips->get_data($cue_sheets);

and finally to your view

foreach($clips as $clip){
echo $clip->clip_name;
}

Hope it helps

回答3:

As far as I know, there's not really a way to pass data back to the controller from the view. I myself have not ever felt the need to. Your controller should be gathering the data and then passing it to the view. If you have additional data to get from your database results, do that first and then pass it to your view along with the original data.

Maybe I'm not understanding your question though...

回答4:

I'm not fully certain I understand you, but I think you want to get all "clips" from all "sheets" given by the first db call. Perhaps following might work:

$this->db->from('clips');
$this->db->where_in('sheet_id', array_map( function($sheet) { return $sheet['id'] }, $data['get_cue_sheets']->result_array() ) );
$data['get_clips'] = $this->db->get();