How to store multiple checkbox value from dropdown into databse using codeigniter?

Question

I am using multiselect jquery plugin for dropdown which allows multiple values to be selected with check boxes.. I am trying to store those values into database.. In view if i use [] symbol in name attribute of input tag, it gives error .. if i don't use that symbol, only one value will be stored. since multiple values are selected here it is an array so this [] symbol has to be used here.... please help me solve this...

my view is

<div class="col-md-8 col-lg-offset-2">
  <label>Select User Name <i class="required"> * </i> </label>

  <select name="user_id" class="form-control">
               <?php foreach($user->result() as $link){ ?>
                <option value="<?php echo $link->user_id ?>"><?php echo $link->username ?></option>
              <?php } ?>
            </select>
</div>

<div class="col-md-8 col-lg-offset-2">
  <label>Select Course Name <i class="required"> * </i> </label>

  <select name="course_id[]" class="form-control" multiple id="course_id">
               <?php foreach($course->result() as $link){ ?>
                <option value="<?php echo $link->id ?>"><?php echo $link->title ?></option>
              <?php } ?>
            </select>
</div>

<div class="col-md-8 col-lg-offset-2">
  <label>Download Access<i class="required"> * </i> </label>
  <select class="form-control" name="access" id="access">
                        <option value=''>--Select Access Type--</option>
                        <option value="yes" <?php echo set_select('access', 'yes'); ?> >Yes</option>
                        <option value="no" <?php echo set_select('access', 'no'); ?> > No</option>    
                    </select>

</div>

my controller is

function add() {

  $this - > _add_set_rules();
  $data = array();

  if ($this - > form_validation - > run() == FALSE) {
    $data['user'] = $this - > user_course_model - > get_user();
    $data['course'] = $this - > user_course_model - > get_course();
    $this - > load - > view('permission/user_course_view', array('left_sidebar' => 'sidebar/left_sidebar', 'right_sidebar' => 'sidebar/right_sidebar'), $data, TRUE);

  } else {
    //Save and redirect..
    $data = $this - > input - > post();

    $inputs_array = array('course_id' => $data['course_id'],
      'user_id' => $data['user_id'],
      'download_access' => $data['access']
    );

    $inserted_id = $this - > user_course_model - > save_user_course($inputs_array);
    //  print_r($inserted_id);
    // exit();
    if ($inserted_id) {
      $this - > session - > set_flashdata('msg', "Access  created successfully..");
      redirect(base_url().
        'user_course', 'refresh');
    } else {
      $this - > session - > set_flashdata('errormsg', "Something went wrong please contact admin.");
      redirect(base_url().
        'user_course', 'refresh');
    }

  }

}

function _add_set_rules() {
  $this - > form_validation - > set_rules('user_id', 'User Name', 'trim||xss_clean|required');
  $this - > form_validation - > set_rules('access', '  Access', 'trim||xss_clean|required');
  $this - > form_validation - > set_rules('course_id[]', ' Course Title', 'trim||xss_clean|required');


}

my model is

function save_user_course($inputs_array) {
  $this - > db - > insert('user_course', $inputs_array);
  return ($this - > db - > affected_rows() != 1) ? false : $this - > db - > insert_id();

}

Table Structure

id course_id user_id download_access

Answer 1

Check the following line:

$inputs_array = array('course_id' => $data['course_id'],
      'user_id' => $data['user_id'],
      'download_access' => $data['access']
    );

    $inserted_id = $this - > user_course_model - > save_user_course($inputs_array);

here $data['course_id'] is an array, and you cannot add an array directly to the database table.