Codeigniter 3: Unknown column 'submit' in 'field list' - codeigniter

Question

I am making a CRUD application with Codeignater 3.
I have an "Add Customers" form with First name, Last name, Email address, City and a submit button.
The model looks like this:
class Customer extends CI_Model {
public function saveCustomer($data) {
$tbl = $this->db->dbprefix('customers');
$this->db->insert($tbl, $data);
}
}
The controller:
if ($this->form_validation->run()) {
$data = $this->input->post();
$this->load->model('Customer');
if ($this->Customer->saveCustomer($data)) {
$this->session->set_flashdata('response','Customer successfully added');
} else {
$this->session->set_flashdata('response','Failed to save customer');
}
return redirect('home');
}
The View file:
<?php echo form_open('home/save'); ?>
<div class="form-group <?php if(form_error('first_name')) echo 'has-error';?>">
<?php echo form_input('first_name', '', [
'type' => 'text',
'id' => 'first_name',
'class' => 'form-control',
'value' => '',
'placeholder' => 'First name',
]);
?>
<?php echo form_error('first_name'); ?>
</div>
<div class="form-group <?php if(form_error('last_name')) echo 'has-error';?>">
<?php echo form_input('last_name', '', [
'type' => 'text',
'id' => 'last_name',
'class' => 'form-control',
'value' => '',
'placeholder' => 'Last name',
]);
?>
<?php echo form_error('last_name'); ?>
</div>
<div class="form-group <?php if(form_error('email')) echo 'has-error';?>">
<?php echo form_input('email', '', [
'type' => 'text',
'id' => 'email',
'class' => 'form-control',
'value' => '',
'placeholder' => 'Email address',
]);
?>
<?php echo form_error('email'); ?>
</div>
<div class="form-group">
<?php echo form_input('phone', '', [
'type' => 'text',
'id' => 'phone',
'class' => 'form-control',
'value' => '',
'placeholder' => 'Phone number',
]);
?>
</div>
<div class="form-group">
<?php echo form_input('city', '', [
'type' => 'text',
'id' => 'city',
'class' => 'form-control',
'value' => '',
'placeholder' => 'City',
]);
?>
</div>
<div class="form-group">
<?php echo form_input('address', '', [
'type' => 'text',
'id' => 'address',
'class' => 'form-control',
'value' => '',
'placeholder' => 'Address',
]);
?>
</div>
<div class="form-group">
<?php echo form_submit('submit', 'Save', 'class = "btn btn-primary btn-block"'); ?>
</div>
<?php echo form_close(); ?>
The problem:
When I submit the form I get this error: Unknown column 'submit' in 'field list'
Why is that?

Answer 1

Change your $data as follows:
$data = array('column_name1' => $this->input->post('first_name'),
'column_name2' => $this->input->post('last_name'),
'column_name3' => $this->input->post('email'),
'column_name4' => $this->input->post('phone'),
'column_name5' => $this->input->post('city'),
'column_name6' => $this->input->post('address'));
NOTE: There is no need of return in controller, only redirect('home') is needed.

Answer 2

Small change in controller
if ($this->form_validation->run()) {
$data = $this->input->post();
//unset your submit value which are come from submit btn
if(isset($data['submit'])){unset($data['submit'])}
if(isset($data->submit)){unset($data->submit)}
$this->load->model('Customer');
if ($this->Customer->saveCustomer($data)) {
$this->session->set_flashdata('response','Customer successfully added');
} else {
$this->session->set_flashdata('response','Failed to save customer');
}
return redirect('home');
}