2019-12-09 13:12:54 +00:00
|
|
|
#include <Functions/IFunctionImpl.h>
|
2018-09-08 01:24:09 +00:00
|
|
|
#include <Functions/FunctionFactory.h>
|
|
|
|
#include <DataTypes/DataTypeNullable.h>
|
|
|
|
#include <Columns/ColumnNullable.h>
|
|
|
|
#include <Core/ColumnNumbers.h>
|
|
|
|
|
|
|
|
|
|
|
|
namespace DB
|
|
|
|
{
|
2020-09-07 18:00:37 +00:00
|
|
|
namespace
|
|
|
|
{
|
2018-09-08 01:24:09 +00:00
|
|
|
|
|
|
|
/// If value is not Nullable or NULL, wraps it to Nullable.
|
|
|
|
class FunctionToNullable : public IFunction
|
|
|
|
{
|
|
|
|
public:
|
|
|
|
static constexpr auto name = "toNullable";
|
|
|
|
|
|
|
|
static FunctionPtr create(const Context &)
|
|
|
|
{
|
|
|
|
return std::make_shared<FunctionToNullable>();
|
|
|
|
}
|
|
|
|
|
|
|
|
std::string getName() const override
|
|
|
|
{
|
|
|
|
return name;
|
|
|
|
}
|
|
|
|
|
|
|
|
size_t getNumberOfArguments() const override { return 1; }
|
|
|
|
bool useDefaultImplementationForNulls() const override { return false; }
|
|
|
|
bool useDefaultImplementationForConstants() const override { return true; }
|
|
|
|
|
|
|
|
DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
|
|
|
|
{
|
|
|
|
return makeNullable(arguments[0]);
|
|
|
|
}
|
|
|
|
|
2020-10-14 13:09:11 +00:00
|
|
|
void executeImpl(ColumnsWithTypeAndName & block, const ColumnNumbers & arguments, size_t result, size_t) const override
|
2018-09-08 01:24:09 +00:00
|
|
|
{
|
2020-10-10 18:24:57 +00:00
|
|
|
block[result].column = makeNullable(block[arguments[0]].column);
|
2018-09-08 01:24:09 +00:00
|
|
|
}
|
|
|
|
};
|
|
|
|
|
2020-09-07 18:00:37 +00:00
|
|
|
}
|
2018-09-08 01:24:09 +00:00
|
|
|
|
|
|
|
void registerFunctionToNullable(FunctionFactory & factory)
|
|
|
|
{
|
|
|
|
factory.registerFunction<FunctionToNullable>();
|
|
|
|
}
|
|
|
|
|
|
|
|
}
|