Method buildSelectWithUnionExpression

src/Analyzer/QueryTreeBuilder.cpp:187–217

}

QueryTreeNodePtr QueryTreeBuilder::buildSelectWithUnionExpression(
    const ASTPtr & select_with_union_query,
    bool is_subquery,
    const CommonTableExpressionData & cte_data,
    const ASTPtr & aliases,
    const ContextPtr & context) const
{
    auto & select_with_union_query_typed = select_with_union_query->as<ASTSelectWithUnionQuery &>();
    auto & select_lists = select_with_union_query_typed.list_of_selects->as<ASTExpressionList &>();

    if (select_lists.children.size() == 1)
        return buildSelectOrUnionExpression(select_lists.children[0], is_subquery, cte_data, aliases, context);

    auto union_node = std::make_shared<UnionNode>(Context::createCopy(context), select_with_union_query_typed.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_with_union_query);

    size_t select_lists_children_size = select_lists.children.size();

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

    return union_node;
}

QueryTreeNodePtr QueryTreeBuilder::buildSelectIntersectExceptQuery(
    const ASTPtr & select_intersect_except_query,