Multi Table Select (Active Records)

I am trying to check multiple databases with user given string. But SQL query always returns true. It must return false, if phone number exist in individual or corporate databases.

Individual Users Database:

Code:

| id |     name     |     phone       |     gender     |
--------------------------------------------------------
| 1  |     John     |     5551928321  |     male       |
| 2  |     Michael  |     5553270543  |     male       |

Corporate Users Database:

Code:

| id |     name     |     phone       |     company    |
--------------------------------------------------------
| 1  |     Megan    |     5553748594  |     demo1      |
| 2  |     Ethan    |     5559182012  |     demo2      |

PHP:

PHP Code:

$phone = '5551928321'; // $this->input->post('phone', true);
$query = $this->db->select('individual.id, corporate.id')
->where('individual.phone', $phone)
->or_where('corporate.phone', $phone)
->get('individual, corporate');

if ($query->num_rows() > 0) echo 'FALSE';
else echo 'TRUE'; 


I will be very pleased if someone light me up for see how it will be work.

Thank you so much.