Method buildSelectIntersectExceptQuery

src/Analyzer/QueryTreeBuilder.cpp:219–260

}

QueryTreeNodePtr QueryTreeBuilder::buildSelectIntersectExceptQuery(
    const ASTPtr & select_intersect_except_query,
    bool is_subquery,
    const CommonTableExpressionData & cte_data,
    const ContextPtr & context) const
{
    auto & select_intersect_except_query_typed = select_intersect_except_query->as<ASTSelectIntersectExceptQuery &>();
    auto select_lists = select_intersect_except_query_typed.getListOfSelects();

    if (select_lists.size() == 1)
        return buildSelectExpression(select_lists[0], is_subquery, cte_data, nullptr /*aliases*/, context);

    SelectUnionMode union_mode = {};
    if (select_intersect_except_query_typed.final_operator == ASTSelectIntersectExceptQuery::Operator::INTERSECT_ALL)
        union_mode = SelectUnionMode::INTERSECT_ALL;
    else if (select_intersect_except_query_typed.final_operator == ASTSelectIntersectExceptQuery::Operator::INTERSECT_DISTINCT)
        union_mode = SelectUnionMode::INTERSECT_DISTINCT;
    else if (select_intersect_except_query_typed.final_operator == ASTSelectIntersectExceptQuery::Operator::EXCEPT_ALL)
        union_mode = SelectUnionMode::EXCEPT_ALL;
    else if (select_intersect_except_query_typed.final_operator == ASTSelectIntersectExceptQuery::Operator::EXCEPT_DISTINCT)
        union_mode = SelectUnionMode::EXCEPT_DISTINCT;
    else
        throw Exception(ErrorCodes::LOGICAL_ERROR, "UNION type is not initialized");

    auto union_node = std::make_shared<UnionNode>(Context::createCopy(context), union_mode);
    union_node->setIsSubquery(is_subquery);
    union_node->setIsCTE(!cte_data.cte_name.empty());
    union_node->setCTEName(std::string(cte_data.cte_name));
    union_node->setIsMaterialized(cte_data.is_materialized);
    union_node->setOriginalAST(select_intersect_except_query);

    size_t select_lists_size = select_lists.size();

    for (size_t i = 0; i < select_lists_size; ++i)
    {
        auto & select_list_node = select_lists[i];
        QueryTreeNodePtr query_node = buildSelectOrUnionExpression(select_list_node, false /*is_subquery*/, {} /*cte_name*/, nullptr /*aliases*/, context);
        union_node->getQueries().getNodes().push_back(std::move(query_node));
    }

    return union_node;
}

QueryTreeNodePtr QueryTreeBuilder::buildSelectExpression(
    const ASTPtr & select_query,