save new fields in database

I found the “save” function in query-builder.php . But I couldn’t find any way to get the info inserted in the new docs form into the database.

I found:

$defaults = array(
				'post_type'    => $this->post_type_name,
				'post_title'   => $_POST['doc']['title'],
				'post_name'    => isset( $_POST['doc']['permalink'] ) ? sanitize_title( $_POST['doc']['permalink'] ) : sanitize_title( $_POST['doc']['title'] ),
				'post_content' => sanitize_post_field( 'post_content', $doc_content, 0, 'db' ),
				'post_status'  => 'publish'
			);

But when i edit this “defaults” to add more fields it doesn’t do anything. My try:

$defaults = array(
				'post_type'    => $this->post_type_name,
				'post_title'   => $_POST['doc']['title'],
				'nr_data_contract' => $_POST['nr_data_contract'],
				'nr_data_fisa' => $_POST['nr_data_fisa'],
				'post_name'    => isset( $_POST['doc']['permalink'] ) ? sanitize_title( $_POST['doc']['permalink'] ) : sanitize_title( $_POST['doc']['title'] ),
				'post_content' => sanitize_post_field( 'post_content', $doc_content, 0, 'db' ),
				'post_status'  => 'publish'
			);

“nr_data_contract” and “nr_data_fisa” are the ids of the new fields in the docs creation page.
Is there something else i have to do to get the data in the database?

Thanks