Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Fix wrong result of cast(float as decimal) when overflow happens (#4380) #4386

Merged
merged 6 commits into from
Apr 13, 2022
Merged

Fix wrong result of cast(float as decimal) when overflow happens (#4380) #4386

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
6 commits
Select commit Hold shift + click to select a range
b55f027
This is an automated cherry-pick of #4380
guo-shaoge Mar 23, 2022
8f9c3df
fix conflicts
guo-shaoge Apr 12, 2022
18ccd98
fix fmt
guo-shaoge Apr 12, 2022
bff94fb
update case
guo-shaoge Apr 12, 2022
2cdd6a6
Merge branch 'cherry-pick-4380-to-release-5.2' of github.com:ti-chi-b…
guo-shaoge Apr 12, 2022
86bc151
Merge branch 'release-5.2' into cherry-pick-4380-to-release-5.2
guo-shaoge Apr 12, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
21 changes: 17 additions & 4 deletions dbms/src/Functions/FunctionsTiDBConversion.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -24,8 +24,8 @@
#include <DataTypes/DataTypeTuple.h>
#include <DataTypes/DataTypeUUID.h>
#include <DataTypes/DataTypesNumber.h>
#include <Flash/Coprocessor/DAGUtils.h>
#include <Flash/Coprocessor/DAGContext.h>
#include <Flash/Coprocessor/DAGUtils.h>
#include <Functions/FunctionFactory.h>
#include <Functions/FunctionHelpers.h>
#include <Functions/FunctionsConversion.h>
Expand Down Expand Up @@ -1162,8 +1162,20 @@ struct TiDBConvertToDecimal
/// cast int/real as decimal
const typename ColumnVector<FromFieldType>::Container & vec_from = col_from->getData();

for (size_t i = 0; i < size; ++i)
vec_to[i] = toTiDBDecimal<FromFieldType, ToFieldType>(vec_from[i], prec, scale, context);
if constexpr (std::is_integral_v<FromFieldType>)
{
/// cast enum/int as decimal
for (size_t i = 0; i < size; ++i)
vec_to[i] = toTiDBDecimal<FromFieldType, ToFieldType>(vec_from[i], prec, scale, context);
}
else
{
/// cast real as decimal
static_assert(std::is_floating_point_v<FromFieldType>);
for (size_t i = 0; i < size; ++i)
// Always use Float64 to avoid overflow for vec_from[i] * 10^scale.
vec_to[i] = toTiDBDecimal<Float64, ToFieldType>(static_cast<Float64>(vec_from[i]), prec, scale, context);
}
}
else
{
Expand Down Expand Up @@ -1751,7 +1763,8 @@ class FunctionTiDBCast final : public IFunctionBase
// other type, its parameter should be the same
DataTypePtr from_inner_type = removeNullable(from_type);
DataTypePtr to_inner_type = removeNullable(to_type);
return !(from_type->isNullable() ^ to_type->isNullable()) && from_inner_type->equals(*to_inner_type) && !from_inner_type->isParametric() && !from_inner_type->isString();
return !(from_type->isNullable() ^ to_type->isNullable()) && from_inner_type->equals(*to_inner_type)
&& !from_inner_type->isParametric() && !from_inner_type->isString();
}

WrapperType prepare(const DataTypePtr & from_type, const DataTypePtr & to_type) const
Expand Down
8 changes: 8 additions & 0 deletions tests/fullstack-test/expr/cast_float_as_decimal.test
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,8 @@
mysql> drop table if exists test.t1;
mysql> create table test.t1(c1 float);
mysql> insert into test.t1 values(3.40282e+37);
mysql> alter table test.t1 set tiflash replica 1;
func> wait_table test t1
mysql> set @@tidb_isolation_read_engines='tiflash'; set @@tidb_enforce_mpp = 1; select cast(c1 as decimal(50, 2)) from test.t1;
cast(c1 as decimal(50, 2))
34028199169636079590747176440761942016.00