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mirror of https://github.com/mariadb-corporation/mariadb-columnstore-engine.git synced 2025-04-23 07:05:36 +03:00
Sergey Zefirov b53c231ca6 MCOL-271 empty strings should not be NULLs (#2794)
This patch improves handling of NULLs in textual fields in ColumnStore.
Previously empty strings were considered NULLs and it could be a problem
if data scheme allows for empty strings. It was also one of major
reasons of behavior difference between ColumnStore and other engines in
MariaDB family.

Also, this patch fixes some other bugs and incorrect behavior, for
example, incorrect comparison for "column <= ''" which evaluates to
constant True for all purposes before this patch.
2023-03-30 21:18:29 +03:00

100 lines
2.3 KiB
C++

/* Copyright (C) 2014 InfiniDB, Inc.
This program 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; version 2 of
the License.
This program 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 this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
MA 02110-1301, USA. */
/****************************************************************************
* $Id: func_repeat.cpp 2477 2011-04-01 16:07:35Z rdempsey $
*
*
****************************************************************************/
#include <cstdlib>
#include <string>
#include <sstream>
using namespace std;
#include "functor_str.h"
#include "functioncolumn.h"
using namespace execplan;
#include "rowgroup.h"
using namespace rowgroup;
#include "joblisttypes.h"
using namespace joblist;
namespace funcexp
{
CalpontSystemCatalog::ColType Func_repeat::operationType(FunctionParm& fp,
CalpontSystemCatalog::ColType& resultType)
{
// operation type is not used by this functor
// return fp[0]->data()->resultType();
return resultType;
}
std::string Func_repeat::getStrVal(rowgroup::Row& row, FunctionParm& fp, bool& isNull,
execplan::CalpontSystemCatalog::ColType& type)
{
string str;
stringValue(fp[0], row, isNull, str);
if (isNull)
return "";
int count = fp[1]->data()->getIntVal(row, isNull);
if (isNull)
return "";
if (count < 1)
{
isNull = true;
return "";
}
// calculate size of buffer to allocate
int size = str.length() * count;
// allocate memory
char* result = new char[size + 1];
if (result == NULL)
{
isNull = true;
return "";
}
memset((char*)result, 0, size + 1);
for (int i = 0; i < count; i++)
{
if (strcat(result, str.c_str()) == NULL) // questionable check
{
isNull = true;
return "";
}
}
std::string res(result);
delete[] result;
return res;
}
} // namespace funcexp