ClickHouse/src/Parsers/ASTSetQuery.h
Alexey Milovidov 7915ba253b Better version
2023-07-17 04:49:04 +02:00

46 lines
1.5 KiB
C++

#pragma once
#include <Core/Names.h>
#include <Parsers/IAST.h>
#include <Common/SettingsChanges.h>
namespace DB
{
constexpr char QUERY_PARAMETER_NAME_PREFIX[] = "param_";
/** SET query
*/
class ASTSetQuery : public IAST
{
public:
bool is_standalone = true; /// If false, this AST is a part of another query, such as SELECT.
/// To support overriding certain settings in a **subquery**, we add a ASTSetQuery with Settings to all subqueries, containing
/// the list of all settings that affect them (specifically or globally to the whole query).
/// We use `print_in_format` to avoid printing these nodes when they were left unchanged from the parent copy
/// See more: https://github.com/ClickHouse/ClickHouse/issues/38895
bool print_in_format = true;
SettingsChanges changes;
/// settings that will be reset to default value
std::vector<String> default_settings;
NameToNameMap query_parameters;
/** Get the text that identifies this element. */
String getID(char) const override { return "Set"; }
ASTPtr clone() const override { return std::make_shared<ASTSetQuery>(*this); }
void formatImpl(const FormatSettings & format, FormatState &, FormatStateStacked) const override;
void updateTreeHashImpl(SipHash & hash_state) const override;
QueryKind getQueryKind() const override { return QueryKind::Set; }
void appendColumnName(WriteBuffer & ostr) const override;
void appendColumnNameWithoutAlias(WriteBuffer & ostr) const override { return appendColumnName(ostr); }
};
}