Uploading image name to the database

[eluser]Unknown[/eluser]
hi i am new the CI , i have successfully uploaded the file to the server but in order to retrieve the image must put in database.

can anyone help me of this

i have done like this

$upload_data = $this->upload->data();
$filename = $upload_data['file_name'];

$this->load->model('register');
if($query = $this->register->registration($filename))
{
echo 'inserted';
}
else
{
echo 'error';
}
from here how can i insert into the model ,anyone please help for me...