I’m trying to query the contacts database with the help of filter, I’m using the following code to add filters

contacts_filter_h filter;
res = contacts_filter_create(_contacts_number._uri, &filter);
	if (res != CONTACTS_ERROR_NONE) {
		dlog_print(DLOG_DEBUG, "test", "contacts_filter_create-->Error-->%s",
				get_error_message(res));
	}
res = contacts_filter_add_str(filter, _contacts_number.number,
			CONTACTS_MATCH_FULLSTRING, "11111");
	if (res != CONTACTS_ERROR_NONE) {
		dlog_print(DLOG_DEBUG, "test", "contacts_filter_add_str-->Error-->%s",
				get_error_message(res));
	}

In the function catacts_filter_add_str I’m gettign “INVALID PARAMETER” error. I know that the type of the _contacts_number.number is not string but, I have no clue on how to query on the phone number.