Data update is not working without profile picture - php

Question

In php when I am updating user info into database with profile image then updation is working but when I'm not selecting image then the update is not working.
Here is my controller:
public function editvendor($id = '') {
$this->authAdLogin();
if ($id == '') {
redirect(admin_url() . 'vendorlisting');
} else if ($this->db->where('id', $id)->get('tbl_vendor')->num_rows() == 0) {
redirect(admin_url() . 'vendorlisting');
} else {
$data['vendor_data'] = $this->db->where('id', $id)->get('tbl_vendor')->result_array();
$vendor_data = $data['vendor_data'];
$this->form_validation->set_rules('contact_name', 'Name', 'trim|xss_clean|required');
$this->form_validation->set_rules('contact_mobile', 'Mobile Number', 'trim|xss_clean|required|numericmin_length[10]|max_length[10]');
$this->form_validation->set_rules('contact_land', 'Landline Number', 'trim|xss_clean|numeric');
$this->form_validation->set_rules('contact_email', 'Email', 'trim|xss_clean|required|valid_email');
$this->form_validation->set_rules('incorporation_date', 'Incorporation Date', 'trim|xss_clean|required');
$this->form_validation->set_rules('pancard_no', 'Pan Card', 'trim|xss_clean|required');
$this->form_validation->set_rules('tan_no', 'Tan Number', 'trim|xss_clean|required');
$this->form_validation->set_rules('tin_no', 'Tin Number', 'trim|xss_clean|required');
$this->form_validation->set_rules('service_no', 'Service Number', 'trim|xss_clean|required');
if ($this->form_validation->run() == false) {
$this->load->view('admin/header');
$this->load->view('admin/sidemenu');
$this->load->view('admin/editvendor', $data);
} else {
$id = $vendor_data[0]['id'];
$upload_dir = './uploads/' . $vendor_data[0]['vendor_id'];
if (!is_dir($upload_dir)) {
mkdir($upload_dir);
}
if (isset($_FILES['profile_pic']['name'])) {
$config['upload_path'] = './uploads/' . $vendor_data[0]['vendor_id'];
$config['allowed_types'] = 'gif|jpg|png';
/* $config['max_size'] = '1000000';
$config['max_width'] = '10240000';
$config['max_height'] = '7680000'; */
$config['file_name'] = "prof_" . rand(1, 5000);
$this->load->library('upload');
$this->upload->initialize($config);
if (!$this->upload->do_upload('profile_pic')) {
$error = $this->upload->display_errors();
$this->session->set_flashdata('ppic_error', $error);
redirect(admin_url() . 'editvendor');
} else {
$data = $this->upload->data();
$prof_pic = $data['file_name'];
}
} else {
$prof_pic = $vendor_data[0]['profile_pic'];
}
$update_data = array(
'contact_name' => $this->input->post('contact_name'),
'contact_mobile' => $this->input->post('contact_mobile'),
'contact_land' => $this->input->post('contact_land'),
'contact_email' => $this->input->post('contact_email'),
'mailing_address' => $this->input->post('mailing_address'),
'incorporation_date' => $this->input->post('incorporation_date'),
'pancard_no' => $this->input->post('pancard_no'),
'tan_no' => $this->input->post('mailing_address'),
'mailing_address' => $this->input->post('tan_no'),
'tin_no' => $this->input->post('tin_no'),
'service_no' => $this->input->post('service_no'),
'web_url' => $this->input->post('web_url'),
'business_address' => $this->input->post('business_address'),
'other_certificates' => $this->input->post('other_certificates'),
'facebook_link' => $this->input->post('facebook_link'),
'twitter_link' => $this->input->post('twitter_link'),
'linkedin_link' => $this->input->post('linkedin_link'),
'googleplus_link' => $this->input->post('googleplus_link'),
'about_company' => $this->input->post('about_company'),
'industry_segment' => $this->input->post('industry_segment'),
'ayurveda' => $this->input->post('ayurveda'),
'homeopathy' => $this->input->post('homeopathy'),
'unani' => $this->input->post('unani'),
'profile_pic' => $prof_pic,
);
$this->db->where('id', $id);
$this->db->update('tbl_vendor', $update_data);
$this->session->set_flashdata('vendor_edit', 'Successfully updated.');
redirect(admin_url() . 'editvendor/' . $id);
}
}
}
Please
provide any solution.