Codeigniter $ query-> result（）循环到关联数组

Question

I'm having trouble getting this loop to return all of the rows that I know mysql is generating in this query. The objects in my javascript console are returning as I would like them to; however, I'm only getting the last row from each unique $row->student_id . I can tell that each unique row->student_id is being overwritten by the previous, but I'm not sure how else to do this logic.

This is part of a Codeigniter model. My controller is performing a json_encode function on this function, then I'm pulling this data into my view with jQuery $.ajax wired to a handlebars.js template. I'm aware that I could use ember for data bindings, but that is beyond my expertise at this time.

$query = $this->db->get();
    if ($query->num_rows() > 0) {

        $prev = null;
        foreach ($query->result() as $row) {

            if ($prev != $row->student_id) {
                $data[$row->student_id] = array(
                    'first' => $row->last_name,
                    'last' => $row->first_name);
                $data[$row->student_id]['dorc'] = array($row->debit_or_credit);
                $prev = $row->student_id;
            } else {
                $data[$row->student_id]['dorc'][] += $row->debit_or_credit;

            }
        }

        return $data;
    } else {
        return array();
    }`

Answer 1

Your second if condition is not correct. You should replace it by this :

foreach ($query->result() as $row) {
    if (!isset($data[$row->student_id])) { // Creates the row if not exists
        $data[$row->student_id] = array(
                            'first' => $row->last_name,
                            'last' => $row->first_name);
    }

    if (!isset($data[$row->student_id]['dorc'])) { // Create the dorc key if not exists
        $data[$row->student_id]['dorc'] = array($row->debit_or_credit);
    } else { // if it exists, push the debit_or_credit row value
        $data[$row->student_id]['dorc'][] = $row->debit_or_credit;
    }
}