Files
secondo/Algebras/NestedRelation2/Rename.h
2026-01-23 17:03:45 +08:00

76 lines
2.2 KiB
C++

/*
----
This file is part of SECONDO.
Copyright (C) 2004, University in Hagen, Department of Computer Science,
Database Systems for New Applications.
SECONDO is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
SECONDO is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with SECONDO; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
----
1.1 Rename
This operator postfixes each attribut name of a tuple stream with an
underscore and a given postfix. This is done for subrelations too.
*/
#ifndef ALGEBRAS_NESTEDRELATION2_OPERATORS_RENAME_H_
#define ALGEBRAS_NESTEDRELATION2_OPERATORS_RENAME_H_
#include "Stream.h"
namespace nr2a {
class Rename
{
public:
struct Info : OperatorInfo
{
Info()
{
name = "rename";
signature = "stream(tuple(X)) -> stream(tuple(Y))";
syntax = "_ rename[ _ ]";
meaning = "Renames all attribute names by adding"
" them with the postfix passed as parameter. "
"It can also be used by its short form.";
example = "query publishers feed {s} consume";
}
};
virtual ~Rename();
static ListExpr MapType(ListExpr args);
static ValueMapping functions[];
static int SelectFunction(ListExpr args);
static int RenameValue(Word* args, Word& result, int message,
Word& local, Supplier s);
static CreateCostEstimation costEstimators[];
protected:
private:
Rename();
// Declared, but not defined => Linker error on usage
static bool RenameTypes(const ListExpr type, const std::string & postfix,
ListExpr & outType, std::string & errorMsg, const bool sub=false);
};
} /* namespace nr2a*/
#endif /* ALGEBRAS_NESTEDRELATION2_OPERATORS_RENAME_H_*/