Method parseOrderBy

cpp_src/core/query/sql/sqlparser.cc:400–464

template <typename Sortable>
void SQLParser::parseOrderBy(Tokenizer& parser, Sortable& sortable) {
	// Just skip token (BY)
	std::ignore = peekSqlToken(parser, BySqlToken);
	parser.SkipToken();
	Token tok, nameWithCase;
	for (;;) {
		nameWithCase = peekSqlToken(parser, FieldNameSqlToken, false);
		if (nameWithCase.Type() != TokenName && nameWithCase.Type() != TokenString) {
			const auto range = parser.Where(nameWithCase);
			throw SqlParserError(range, "Expected name, but found '{}' in query, {}", nameWithCase.Text(), range);
		}
		tok = parser.NextToken(Tokenizer::Flags::InOrderBy);
		std::string sortExpression(tok.Text());
		if (sortExpression.empty()) {
			const auto range = parser.Where(tok);
			throw SqlParserError(range, "Order by expression should not be empty, {}", range);
		}
		tok = peekSqlToken(parser, SortDirectionSqlToken);
		std::vector<Variant> forcedSortOrder;
		if (tok.Text() == "("sv && iequals(nameWithCase.Text(), "field"sv)) {
			if constexpr (std::is_same_v<Sortable, AggregateEntry>) {
				const auto range = parser.Where(tok);
				throw SqlParserError(range, "Forced sort order is not available in aggregation sort");
			}
			parser.SkipToken();
			nameWithCase = peekSqlToken(parser, FieldNameSqlToken, false);
			if (nameWithCase.Type() != TokenName) {
				const auto range = parser.Where(nameWithCase);
				throw SqlParserError(range, "Expected name, but found '{}' in query, {}", nameWithCase.Text(), range);
			}
			sortExpression = nameWithCase.Text();
			tok = parser.NextToken(Tokenizer::Flags::NoFlags);
			for (;;) {
				tok = parser.NextToken();
				if (tok.Text() == ")"sv) {
					break;
				}
				if (tok.Text() != ","sv) {
					const auto range = parser.Where(tok);
					throw SqlParserError(range, "Expected ')' or ',', but found '{}' in query, {}", tok.Text(), range);
				}
				tok = parser.NextToken();
				forcedSortOrder.push_back(Token2kv(tok, parser, CompositeAllowed_True, FieldAllowed_False, NullAllowed_False));
			}
			tok = parser.PeekToken();
		}

		bool desc = false;
		if (tok.Text() == "asc"sv || tok.Text() == "desc"sv) {
			desc = tok.Text() == "desc"sv;
			parser.SkipToken();
		}
		if constexpr (std::is_same_v<Sortable, AggregateEntry>) {
			sortable.Sort(std::move(sortExpression), desc);
		} else {
			sortable.Sort(std::move(sortExpression), desc, std::move(forcedSortOrder));
		}