Method visitChildren

src/Interpreters/QueryNormalizer.cpp:397–437

Don't go into subqueries. Don't go into select query. It processes children itself. Do not go to the left argument of lambda expressions, so as not to replace the formal parameters on aliases in expressions of the form 123 AS x, arrayMap(x -> 1, [2]).

/// Do not go to the left argument of lambda expressions, so as not to replace the formal parameters
///  on aliases in expressions of the form 123 AS x, arrayMap(x -> 1, [2]).
void QueryNormalizer::visitChildren(IAST * node, Data & data)
{
    if (auto * func_node = node->as<ASTFunction>())
    {
        if (func_node->tryGetQueryArgument())
        {
            if (func_node->name != "view")
                throw Exception("Query argument can only be used in the `view` TableFunction", ErrorCodes::BAD_ARGUMENTS);
            /// Don't go into query argument.
            return;
        }
        /// We skip the first argument. We also assume that the lambda function can not have parameters.
        size_t first_pos = 0;
        if (func_node->name == "lambda")
            first_pos = 1;

        if (func_node->arguments)
        {
            auto & func_children = func_node->arguments->children;

            for (size_t i = first_pos; i < func_children.size(); ++i)
            {
                auto & child = func_children[i];

                if (needVisitChild(child))
                    visit(child, data);
            }
        }

        if (func_node->window_definition)
        {
            visitChildren(func_node->window_definition.get(), data);
        }
    }
    else if (!node->as<ASTSelectQuery>() && !node->as<ASTTablesInSelectQueryElement>())
    {
        for (auto & child : node->children)
            if (needVisitChild(child))
                visit(child, data);
    }
}

void QueryNormalizer::visit(ASTPtr & ast, Data & data)
{