Insert Multiple in dropdown

Dear all can you help me to resolve this error?

Error
A PHP Error was encountered
Severity: Notice
Message: Array to string conversion
Filename: database/DB_driver.php
Line Number: 1477
Backtrace:
File: C:\wamp64\www\MY\admin\application\models\User_model.php
Line: 37
Function: insert
File: C:\wamp64\www\MY\admin\application\controllers\User.php
Line: 28
Function: insert_data
File: C:\wamp64\www\MY\admin\index.php
Line: 315
Function: require_once

Model

PHP Code:

<?php

Class User_model extends CI_Model
{

    public function __construct()
    {
        parent::__construct();

    }

    public function all_forms()
    {

    }

    function get_location()
    {
        $query = $this->db->query("SELECT * FROM location");
        $result = $query->result();
        return $result;

    }

    function insert_data()
    {
        $now = date_default_timezone_set('Asia/Colombo'); // Set Time-Zone
        $now = date('Y-m-d H:i'); //Fomat Date and time
        $data["place"] = $this->input->post("place");
        $data["request_date"] = $this->input->post("request_date");
        $data["location_id"] = $this->input->post("location_id");
        $data["user"] = $this->session->userdata("ID");
        $data["request_by"] = $this->input->post("requested_by");
        $data["comments"] = $this->input->post("comments");
        $data["date"]= $now;
        $data["urgency"] = $this->input->post("urgency");
        $this->db->insert('requisition', $data);
       

        $this->load->library('email', $config);
        $this->email->set_newline("\r\n");

        $this->email->from('[email protected]', 'Sanjaya prasanna');
        $this->email->to('[email protected]');
        // $this->email->cc('[email protected]');
        //$this->email->bcc('[email protected]');

        //Setup Email Body..
        $place = "<p style='color: darkorange'>Place</p>";
        $date = "<p style='color: darkorange'>Date</p>";
        $request_by = "<p style='color: darkorange'>Requested By</p>";
        $urgency = "<p style='color: darkorange'>Urgency</p>";
        $heading = "<h2 style='text-align: center; color: darkorange'>New Requisition has been arrived !</h2></br>";
        $time = "<p style='color: darkorange'>Requested Time</p>";
        $this->email->subject('New Requisition has been arrived !');
        $this->email->message($heading.$place.$data['place'] = $this->input->post('place').'<br>'.$date.$data["request_date"] = $this->input->post("request_date").'<br>'.$request_by.$data["request_by"] = $this->input->post("requested_by").'<br>'.$urgency.$data["urgency"] = $this->input->post("urgency").'<br>'.$time.$data["date"]= $now);

        if($this->email->send())
        {
           // echo "Your Email Has Been Sent.";
        }
        else
        {
            show_error($this->email->print_debugger());
            echo "Your Request not sent. Try again later";
        }

    }




} 


Controller: 

PHP Code:

<?php
defined('BASEPATH') OR exit('No direct script access allowed');

class User extends CI_Controller
{

    public function __construct()
    {
        parent::__construct();
        $this->load->model("Login_model");
        $this->load->library('session');
    }

    public function index()
    {
        if ($this->session->userdata("NAME"))
        {
            $role = $this->session->userdata("ROLE");
            if ($role >= 0)
            {
                if ($this->input->post()) {
                    $this->form_validation->set_rules('place', 'Place of visit', 'required|max_length[100]');
                    $this->form_validation->set_rules('request_date', 'Requested Date', 'required');
                    $this->form_validation->set_rules('requested_by', 'Request By', 'required');

                    if ($this->form_validation->run() === TRUE) {
                        $this->load->model('User_model');
                        $this->User_model->insert_data();
                        $this->session->set_flashdata('message_name', 'Your Requisition has been sent to the administrator');
                        redirect('user/index');

                    }
                }

                $this->load->model("Supporter_model");
                $data["movement_data"] = $this->Supporter_model->movement_list();

                $this->load->model("User_model");
                $data["location"] = $this->User_model->get_location();

                $this->load->model("Requisition_model");
                $data["requisition"] = $this->Requisition_model->public_view();
                $this->load->view('user/public', $data);
            }
        }else
        {
            $this->session->set_flashdata('message_name', 'Your session has been expired. Please Login');
            redirect('login/employee_login');
        }
    }

} 


View: 

PHP Code:

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <title>SGH-EMS Supreme Global Holdings </title>
    <!-- Tell the browser to be responsive to screen width -->
    <meta content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no" name="viewport">
    <!-- Bootstrap 3.3.7 -->
    <link rel="stylesheet" href="<?php echo base_url(); ?>assets/bower_components/bootstrap/dist/css/bootstrap.min.css">
    <!-- Font Awesome -->
    <link rel="stylesheet" href="<?php echo base_url(); ?>assets/bower_components/font-awesome/css/font-awesome.min.css">
    <!-- Ionicons -->
    <link rel="stylesheet" href="<?php echo base_url(); ?>assets/bower_components/Ionicons/css/ionicons.min.css">
    <link rel="stylesheet" href="<?php echo base_url(); ?>assets/bower_components/bootstrap-daterangepicker/daterangepicker.css">
    <!-- bootstrap datepicker -->
    <link rel="stylesheet" href="<?php echo base_url(); ?>assets/bower_components/bootstrap-datepicker/dist/css/bootstrap-datepicker.min.css">
    <!-- iCheck for checkboxes and radio inputs -->
    <link rel="stylesheet" href="<?php echo base_url(); ?>assets/plugins/iCheck/all.css">
    <!-- Bootstrap Color Picker -->
    <link rel="stylesheet" href="<?php echo base_url(); ?>assets/bower_components/bootstrap-colorpicker/dist/css/bootstrap-colorpicker.min.css">
    <!-- Bootstrap time Picker -->
    <link rel="stylesheet" href="<?php echo base_url(); ?>assets/plugins/timepicker/bootstrap-timepicker.min.css">
    <!-- Select2 -->
    <link rel="stylesheet" href="<?php echo base_url(); ?>assets/bower_components/select2/dist/css/select2.min.css">
    <!-- DataTables -->
    <link rel="stylesheet" href="<?php echo base_url(); ?>assets/bower_components/datatables.net-bs/css/dataTables.bootstrap.min.css">
    <!-- Theme style -->
    <link rel="stylesheet" href="<?php echo base_url(); ?>assets/dist/css/AdminLTE.min.css">
    <link rel="stylesheet" href="<?php echo base_url(); ?>assets/dist/css/sghems.css">
    <!-- AdminLTE Skins. Choose a skin from the css/skins
         folder instead of downloading all of them to reduce the load. -->
    <link rel="stylesheet" href="<?php echo base_url(); ?>assets/dist/css/skins/_all-skins.min.css">
    <link rel="stylesheet" href="<?php echo base_url(); ?>assets/plugins/bootstrap-wysihtml5/bootstrap3-wysihtml5.min.css">

    <!-- HTML5 Shim and Respond.js IE8 support of HTML5 elements and media queries -->
    <!-- WARNING: Respond.js doesn't work if you view the page via file:// -->
    <!--[if lt IE 9]>
    <script src="https://oss.maxcdn.com/html5shiv/3.7.3/html5shiv.min.js"></script>
    <script src="https://oss.maxcdn.com/respond/1.4.2/respond.min.js"></script>
    <![endif]-->

    <!-- Google Font -->
    <link rel="stylesheet"
          href="https://fonts.googleapis.com/css?family=Source+Sans+Pro:300,400,600,700,300italic,400italic,600italic">
<body style="background-color: rgba(0, 0, 0, 0.9); background-image: url(<?php echo base_url();?>)/ui2/assets/backgrounds/2.jpg; ">

<nav class="navbar navbar-static-top navbar-fixed-top head" >
    <div class="container">
        <div class="navbar-header">
            <img src="<?php echo base_url();?>/ui2/assets/img/logo1.png" style="padding-top: 15px">
            <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#navbar-collapse">
                <i class="fa fa-bars"></i>
            </button>
        </div>

        <!-- Collect the nav links, forms, and other content for toggling -->
        <div class="collapse navbar-collapse pull-right" id="navbar-collapse">
            <ul class="nav navbar-nav">
                <li><a href="<?= base_url()?>dashboard/index">Dashboard</a></li>
                <li><a href="<?= base_url()?>login/reset_password/">Forgot Password ?</a></li>
                <li><a href="<?= base_url()?>supporter/index">Supporters</a></li>
                <li><a href="<?= base_url()?>login/logout/">Logout</a></li>
            </ul>
        </div>
        <!-- /.navbar-collapse -->
    </div>
    <!-- /.container-fluid -->
</nav>
<!-- Full Width Column -->

<div class="container">
    <!-- Content Header (Page header) -->
    <section class="content-header">
        <h1 class="text-center" style="color: #ffffff; font-size: 34px;">
            Daily Movement Requisition
        </h1>
    </section>

    <!-- Main content -->
    <section class="content">
        <div class="row">
            <div class="col-sm-7" >
                <div style="background-color: #FFFFff; padding: 5px;">
                    <section class="content-header">
                        <h1 class="text-center" style="color: #000000; padding-bottom: 10px;" >
                            MOVEMENT CHART
                        </h1>
                    </section>
                    <table class="table table-striped ">
                        <thead style="background-color: burlywood">
                        <tr>
                            <th class="text-center">ID</th>
                            <th class="text-center">Runner Name</th>
                            <th class="text-center">Place</th>
                            <th class="text-center">Date</th>
                            <th class="text-center">Departure</th>
                            <th class="text-center">Arrival</th>
                        </tr>
                        </thead>
                        <tbody>
                        <?php
                        foreach ($movement_data as $row) {

                            ?>
                            <tr>
                                <td class="text-center"><?=$row["id"]?></td>
                                <td class="text-center"><?=$row["runner_name"]?></td>
                                <td class="text-center"><?=$row["place"]?></td>
                                <td class="text-center"><?=$row["date"]?></td>
                                <td class="text-center"><?=$row["departure"]?></td>
                                <td class="text-center"><?=$row["arrival"]?></td>
                            </tr>
                        <?php }
                        ?>
                        </tbody>
                    </table>
                </div>

                <div style="background-color: #FFFFff; padding: 5px; margin-top: 10px;">
                    <section class="content-header">
                        <h1 class="text-center" style="color: #000000; padding-bottom: 10px;  " >
                            REQUISITIONS CHART
                        </h1>
                    </section>
                    <table class="table table-striped ">
                        <thead style="background-color: burlywood">
                        <tr>
                            <th>Requisition ID</th>
                            <th>Location Name</th>
                            <th>Place</th>
                            <th>Request By</th>
                            <th>Request Time</th>
                        </tr>
                        </thead>
                        <tbody>
                        <?php
                        foreach ($requisition as $row) {

                            ?>
                            <tr>
                                <td><?=$row['id']?></td>
                                <td><?=$row['location_name']?></td>
                                <td><?=$row['place']?></td>
                                <td><?=$row['request_by']?></td>
                                <td><?=$row['date']?></td>
                            </tr>
                        <?php }
                        ?>
                        </tbody>
                    </table>
                </div>
            </div>
            <div class="col-sm-5" style="background-color: rgba(0, 0, 0, 0.9)">
                <section class="content-header">
                    <h1 class="text-center" style="color: #E4BC3A">
                        Daily Movement Requisition Form
                    </h1>
                </section>
                <span class="text-danger"><?php echo validation_errors() ?></span>
                <form action="<?=base_url()?>user/index" method="post">
                    <div class="box-body">
                        <div class="form-group">
                            <label style="color: #E4BC3A; font-size: 18px;">Place of visit</label>
                            <input type="text" class="form-control" name="place">
                        </div>
                    </div>
                    <div class="box-body">
                            <div class="form-group">
                                <label style="color: #E4BC3A; font-size: 18px">Location</label>
                                <select class="form-control select2" multiple="multiple" style="width: 100%;" name="location_id[]">
                                    <option>Please Select Location</option>
                                    <?php
                                    foreach ($location as $location_details){
                                        ?>
                                        <option value="<?php echo $location_details->id ?>"><?php echo $location_details->location_name ?></option>
                                    <?php }
                                    ?>
                                </select>
                            </div>
                    </div>
                    <div class="box-body">
                        <div class="form-group">
                            <label style="color: #E4BC3A; font-size: 18px">Comments</label>
                            <textarea class="form-control" name="comments" rows="3" ></textarea>
                        </div>
                    </div>
                    <div class="box-body">
                        <div class="form-group">
                            <label style="color: #E4BC3A; font-size: 18px">Request By</label>
                            <input type="text" class="form-control" name="requested_by">
                        </div>
                    </div>
                    <div class="box-body">
                        <div class="form-group">
                            <div class="form-group">
                                <label style="color: #E4BC3A; font-size: 18px">Urgency</label>
                                <select class="form-control select2" style="width: 100%;" name="urgency">
                                    <option>Select Your Urgency</option>
                                    <option>Select Your Urgency</option>
                                    <option value="Now itself">Now itself.</option>
                                    <option value="Within the next hour.">Within the next hour.</option>
                                    <option value="Within next 2 - 3 hours.">Within next 2 - 3 hours.</option>
                                    <option value="Within the course of the day.">Within the course of the day.</option>
                                    <option value="Within the next day.">Within the next day.</option>
                                </select>
                            </div>
                        </div>
                    </div>
                    <div class="box-body">
                        <div class="form-group">
                            <label style="color: #E4BC3A; font-size: 18px">Date</label>

                            <div class="input-group date">
                                <div class="input-group-addon">
                                    <i class="fa fa-calendar"></i>
                                </div>
                                <input type="text" name="request_date" class="form-control pull-right" id="datepicker">
                            </div>
                        </div>

                        <div class="row">
                            <div class="col-md-3">

                            </div>
                            <div class="col-md-3">
                                <button type="submit" class="btn btn-info btn-lg">Save</button>

                            </div>
                            <div class="col-md-3">

                                <button class="btn btn-info btn-lg" type="reset">Reset</button>
                            </div>
                            <div class="col-md-3">

                            </div>
                        </div>
                </form>
            </div>
        </div>
        <!-- /.box -->
    </section>
    <!-- /.content -->
</div>
<!-- /.container -->

<!-- jQuery 3 -->
<script src="<?php echo base_url(); ?>assets/bower_components/jquery/dist/jquery.min.js"></script>

<!-- Bootstrap 3.3.7 -->
<script src="<?php echo base_url(); ?>assets/bower_components/bootstrap/dist/js/bootstrap.min.js"></script>

<!-- InputMask -->
<script src="<?php echo base_url(); ?>assets/plugins/input-mask/jquery.inputmask.js"></script>
<script src="<?php echo base_url(); ?>assets/plugins/input-mask/jquery.inputmask.date.extensions.js"></script>
<script src="<?php echo base_url(); ?>assets/plugins/input-mask/jquery.inputmask.extensions.js"></script>
<!-- date-range-picker -->
<script src="<?php echo base_url(); ?>assets/bower_components/moment/min/moment.min.js"></script>
<script src="<?php echo base_url(); ?>assets/bower_components/bootstrap-daterangepicker/daterangepicker.js"></script>
<!-- bootstrap datepicker -->
<script src="<?php echo base_url(); ?>assets/bower_components/bootstrap-datepicker/dist/js/bootstrap-datepicker.min.js"></script>
<!-- bootstrap color picker -->
<script src="<?php echo base_url(); ?>assets/bower_components/bootstrap-colorpicker/dist/js/bootstrap-colorpicker.min.js"></script>
<!-- bootstrap time picker -->
<script src="<?php echo base_url(); ?>assets/plugins/timepicker/bootstrap-timepicker.min.js"></script>
<!-- DataTables -->
<script src="<?php echo base_url(); ?>assets/bower_components/datatables.net/js/jquery.dataTables.min.js"></script>
<script src="<?php echo base_url(); ?>assets/bower_components/datatables.net-bs/js/dataTables.bootstrap.min.js"></script>
<!-- SlimScroll -->
<script src="<?php echo base_url(); ?>assets/bower_components/jquery-slimscroll/jquery.slimscroll.min.js"></script>
<script src="<?php echo base_url(); ?>assets/plugins/iCheck/icheck.min.js"></script>
<!-- FastClick -->
<script src="<?php echo base_url(); ?>assets/bower_components/fastclick/lib/fastclick.js"></script>
<!-- AdminLTE App -->
<script src="<?php echo base_url(); ?>assets/dist/js/adminlte.min.js"></script>
<script src="<?php echo base_url(); ?>assets/bower_components/ckeditor/ckeditor.js"></script>
<script src="<?php echo base_url(); ?>assets/plugins/bootstrap-wysihtml5/bootstrap3-wysihtml5.all.min.js"></script>
<script src="<?php echo base_url(); ?>assets/bower_components/select2/dist/js/select2.full.min.js"></script>
<!-- AdminLTE for demo purposes -->
<script src="<?php echo base_url(); ?>assets/dist/js/demo.js"></script>
<!-- page script -->
<script>
    $(function () {
        $('#example1').DataTable()
        $('#example2').DataTable({
            'paging'      : true,
            'lengthChange': false,
            'searching'   : false,
            'ordering'    : true,
            'info'        : true,
            'autoWidth'   : false
        })
    })
</script>
<script>

    $(function () {
        //Initialize Select2 Elements
        $('.select2').select2()

        //Datemask dd/mm/yyyy
        $('#datemask').inputmask('dd/mm/yyyy', { 'placeholder': 'dd/mm/yyyy' })
        //Datemask2 mm/dd/yyyy
        $('#datemask2').inputmask('mm/dd/yyyy', { 'placeholder': 'mm/dd/yyyy' })
        //Money Euro
        $('[data-mask]').inputmask()

        //Date range picker
        $('#reservation').daterangepicker()
        //Date range picker with time picker
        $('#reservationtime').daterangepicker({ timePicker: true, timePickerIncrement: 30, format: 'MM/DD/YYYY h:mm A' })
        //Date range as a button
        $('#daterange-btn').daterangepicker(
            {
                ranges   : {
                    'Today'       : [moment(), moment()],
                    'Yesterday'   : [moment().subtract(1, 'days'), moment().subtract(1, 'days')],
                    'Last 7 Days' : [moment().subtract(6, 'days'), moment()],
                    'Last 30 Days': [moment().subtract(29, 'days'), moment()],
                    'This Month'  : [moment().startOf('month'), moment().endOf('month')],
                    'Last Month'  : [moment().subtract(1, 'month').startOf('month'), moment().subtract(1, 'month').endOf('month')]
                },
                startDate: moment().subtract(29, 'days'),
                endDate  : moment()
            },
            function (start, end) {
                $('#daterange-btn span').html(start.format('MMMM D, YYYY') + ' - ' + end.format('MMMM D, YYYY'))
            }
        )

        //Date picker
        $('#datepicker').datepicker({
            autoclose: true
        })

        //iCheck for checkbox and radio inputs
        $('input[type="checkbox"].minimal, input[type="radio"].minimal').iCheck({
            checkboxClass: 'icheckbox_minimal-blue',
            radioClass   : 'iradio_minimal-blue'
        })
        //Red color scheme for iCheck
        $('input[type="checkbox"].minimal-red, input[type="radio"].minimal-red').iCheck({
            checkboxClass: 'icheckbox_minimal-red',
            radioClass   : 'iradio_minimal-red'
        })
        //Flat red color scheme for iCheck
        $('input[type="checkbox"].flat-red, input[type="radio"].flat-red').iCheck({
            checkboxClass: 'icheckbox_flat-green',
            radioClass   : 'iradio_flat-green'
        })

        //Colorpicker
        $('.my-colorpicker1').colorpicker()
        //color picker with addon
        $('.my-colorpicker2').colorpicker()

        //Timepicker
        $('.timepicker').timepicker({
            showInputs: false
        })
    })
</script>
</body>
</html> 


Any one Can help me to resolve this error? I am try to insert multiple items from dropdown

Make a print_r or var_dump before:

Code:

$this->db->insert('requisition', $data);

So it looks like:

Code:

print_r($data);exit;
$this->db->insert('requisition', $data);

Your $data contains invalid data.