ClickHouse/dbms/src/Parsers/ASTOrderByElement.h
2018-12-07 15:34:40 +03:00

43 lines
1.2 KiB
C++

#pragma once
#include <Parsers/IAST.h>
namespace DB
{
/** Element of expression with ASC or DESC,
* and possibly with COLLATE.
*/
class ASTOrderByElement : public IAST
{
public:
int direction; /// 1 for ASC, -1 for DESC
int nulls_direction; /// Same as direction for NULLS LAST, opposite for NULLS FIRST.
bool nulls_direction_was_explicitly_specified;
/** Collation for locale-specific string comparison. If empty, then sorting done by bytes. */
ASTPtr collation;
ASTOrderByElement(
const int direction_, const int nulls_direction_, const bool nulls_direction_was_explicitly_specified_, ASTPtr & collation_)
: direction(direction_)
, nulls_direction(nulls_direction_)
, nulls_direction_was_explicitly_specified(nulls_direction_was_explicitly_specified_)
, collation(collation_)
{
}
String getID(char) const override { return "OrderByElement"; }
ASTPtr clone() const override
{
auto clone = std::make_shared<ASTOrderByElement>(*this);
clone->cloneChildren();
return clone;
}
protected:
void formatImpl(const FormatSettings & settings, FormatState & state, FormatStateStacked frame) const override;
};
}