$sql = "SELECT $contragent_object_table.otvestvenniy_id, 
		$users_table.id AS uid,
        $users_table.first_name AS first_name, 
		$users_table.last_name AS last_name	
		
        FROM $contragent_object_table 
		LEFT JOIN $users_table ON $users_table.id IN (1,2,3,4)
		WHERE $contragent_object_table.deleted=0 $where";

LEFT JOIN $users_table ON $users_table.id IN ($contragent_object_table.otvestvenniy_id)