database/mariadb-columnstore-engine
1
0
Fork 0
mirror of https://github.com/mariadb-corporation/mariadb-columnstore-engine.git synced 2025-07-29 08:21:15 +03:00
Code Activity

MCOL-271 empty strings should not be NULLs (#2794)

Browse Source 
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.
This commit is contained in:
Sergey Zefirov
2023-03-30 17:26:45 +01:00
committed by Roman Nozdrin
parent 0ea592da80
commit b53c231ca6
417 changed files with 12459 additions and 3520 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
utils/funcexp/func_nullif.cpp
View File

@ -348,16 +348,16 @@ uint64_t Func_nullif::getUintVal(rowgroup::Row& row, FunctionParm& parm, bool& i
string Func_nullif::getStrVal(rowgroup::Row& row, FunctionParm& parm, bool& isNull,
CalpontSystemCatalog::ColType& op_ct)
{
string exp1 = parm[0]->data()->getStrVal(row, isNull);
string exp1 = parm[0]->data()->getStrVal(row, isNull).safeString("");
CHARSET_INFO* cs = parm[0]->data()->resultType().getCharset();
if (isNull)
{
isNull = false;
// NULLIF(NULL, ...) is NULL, according to server's results.
return "";
}
string exp2 = parm[1]->data()->getStrVal(row, isNull);
string exp2 = parm[1]->data()->getStrVal(row, isNull).safeString("");
if (isNull)
{
@ -388,7 +388,7 @@ string Func_nullif::getStrVal(rowgroup::Row& row, FunctionParm& parm, bool& isNu
return "";
}
return parm[0]->data()->getStrVal(row, isNull);
return parm[0]->data()->getStrVal(row, isNull).safeString("");
}
int32_t Func_nullif::getDateIntVal(rowgroup::Row& row, FunctionParm& parm, bool& isNull,