mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-12-14 02:12:21 +00:00
165 lines
6.7 KiB
C++
165 lines
6.7 KiB
C++
#include <Functions/FunctionFactory.h>
|
|
#include <Functions/FunctionsConversion.h>
|
|
#include <Functions/CastOverloadResolver.h>
|
|
#include <Interpreters/parseColumnsListForTableFunction.h>
|
|
|
|
|
|
namespace DB
|
|
{
|
|
|
|
namespace ErrorCodes
|
|
{
|
|
extern const int ILLEGAL_TYPE_OF_ARGUMENT;
|
|
}
|
|
|
|
/** CastInternal does not preserve nullability of the data type,
|
|
* i.e. CastInternal(toNullable(toInt8(1)) as Int32) will be Int32(1).
|
|
*
|
|
* Cast preserves nullability according to setting `cast_keep_nullable`,
|
|
* i.e. Cast(toNullable(toInt8(1)) as Int32) will be Nullable(Int32(1)) if `cast_keep_nullable` == 1.
|
|
*/
|
|
template <CastType cast_type, bool internal, typename CastName, typename FunctionName>
|
|
class CastOverloadResolverImpl : public IFunctionOverloadResolver
|
|
{
|
|
public:
|
|
using MonotonicityForRange = FunctionCastBase::MonotonicityForRange;
|
|
|
|
static constexpr auto name = cast_type == CastType::accurate
|
|
? CastName::accurate_cast_name
|
|
: (cast_type == CastType::accurateOrNull ? CastName::accurate_cast_or_null_name : CastName::cast_name);
|
|
|
|
String getName() const override { return name; }
|
|
|
|
size_t getNumberOfArguments() const override { return 2; }
|
|
|
|
ColumnNumbers getArgumentsThatAreAlwaysConstant() const override { return {1}; }
|
|
|
|
explicit CastOverloadResolverImpl(ContextPtr context_, std::optional<CastDiagnostic> diagnostic_, bool keep_nullable_, const DataTypeValidationSettings & data_type_validation_settings_)
|
|
: context(context_)
|
|
, diagnostic(std::move(diagnostic_))
|
|
, keep_nullable(keep_nullable_)
|
|
, data_type_validation_settings(data_type_validation_settings_)
|
|
{
|
|
}
|
|
|
|
static FunctionOverloadResolverPtr create(ContextPtr context)
|
|
{
|
|
const auto & settings_ref = context->getSettingsRef();
|
|
|
|
if constexpr (internal)
|
|
return createImpl(context, {}, false /*keep_nullable*/);
|
|
|
|
return createImpl(context, {}, settings_ref.cast_keep_nullable, DataTypeValidationSettings(settings_ref));
|
|
}
|
|
|
|
static FunctionOverloadResolverPtr createImpl(ContextPtr context, std::optional<CastDiagnostic> diagnostic = {}, bool keep_nullable = false, const DataTypeValidationSettings & data_type_validation_settings = {})
|
|
{
|
|
assert(!internal || !keep_nullable);
|
|
return std::make_unique<CastOverloadResolverImpl>(context, std::move(diagnostic), keep_nullable, data_type_validation_settings);
|
|
}
|
|
|
|
static FunctionOverloadResolverPtr createImpl(std::optional<CastDiagnostic> diagnostic = {}, bool keep_nullable = false, const DataTypeValidationSettings & data_type_validation_settings = {})
|
|
{
|
|
assert(!internal || !keep_nullable);
|
|
return std::make_unique<CastOverloadResolverImpl>(ContextPtr(), std::move(diagnostic), keep_nullable, data_type_validation_settings);
|
|
}
|
|
|
|
protected:
|
|
|
|
FunctionBasePtr buildImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr & return_type) const override
|
|
{
|
|
DataTypes data_types(arguments.size());
|
|
|
|
for (size_t i = 0; i < arguments.size(); ++i)
|
|
data_types[i] = arguments[i].type;
|
|
|
|
auto monotonicity = MonotonicityHelper::getMonotonicityInformation(arguments.front().type, return_type.get());
|
|
return std::make_unique<FunctionCast<FunctionName>>(context, name, std::move(monotonicity), data_types, return_type, diagnostic, cast_type);
|
|
}
|
|
|
|
DataTypePtr getReturnTypeImpl(const ColumnsWithTypeAndName & arguments) const override
|
|
{
|
|
const auto & column = arguments.back().column;
|
|
if (!column)
|
|
throw Exception(ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT, "Second argument to {} must be a constant string describing type. "
|
|
"Instead there is non-constant column of type {}", getName(), arguments.back().type->getName());
|
|
|
|
const auto * type_col = checkAndGetColumnConst<ColumnString>(column.get());
|
|
if (!type_col)
|
|
throw Exception(ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT, "Second argument to {} must be a constant string describing type. "
|
|
"Instead there is a column with the following structure: {}", getName(), column->dumpStructure());
|
|
|
|
DataTypePtr type = DataTypeFactory::instance().get(type_col->getValue<String>());
|
|
validateDataType(type, data_type_validation_settings);
|
|
|
|
if constexpr (cast_type == CastType::accurateOrNull)
|
|
return makeNullable(type);
|
|
|
|
if constexpr (internal)
|
|
return type;
|
|
|
|
if (keep_nullable && arguments.front().type->isNullable() && type->canBeInsideNullable())
|
|
return makeNullable(type);
|
|
|
|
return type;
|
|
}
|
|
|
|
bool useDefaultImplementationForNulls() const override { return false; }
|
|
bool useDefaultImplementationForNothing() const override { return false; }
|
|
bool useDefaultImplementationForLowCardinalityColumns() const override { return false; }
|
|
|
|
private:
|
|
ContextPtr context;
|
|
std::optional<CastDiagnostic> diagnostic;
|
|
bool keep_nullable;
|
|
DataTypeValidationSettings data_type_validation_settings;
|
|
};
|
|
|
|
|
|
struct CastOverloadName
|
|
{
|
|
static constexpr auto cast_name = "CAST";
|
|
static constexpr auto accurate_cast_name = "accurateCast";
|
|
static constexpr auto accurate_cast_or_null_name = "accurateCastOrNull";
|
|
};
|
|
|
|
struct CastInternalOverloadName
|
|
{
|
|
static constexpr auto cast_name = "_CAST";
|
|
static constexpr auto accurate_cast_name = "accurate_Cast";
|
|
static constexpr auto accurate_cast_or_null_name = "accurate_CastOrNull";
|
|
};
|
|
|
|
template <CastType cast_type>
|
|
using CastOverloadResolver = CastOverloadResolverImpl<cast_type, false, CastOverloadName, CastName>;
|
|
|
|
template <CastType cast_type>
|
|
using CastInternalOverloadResolver = CastOverloadResolverImpl<cast_type, true, CastInternalOverloadName, CastInternalName>;
|
|
|
|
|
|
FunctionOverloadResolverPtr createInternalCastOverloadResolver(CastType type, std::optional<CastDiagnostic> diagnostic)
|
|
{
|
|
switch (type)
|
|
{
|
|
case CastType::nonAccurate:
|
|
return CastInternalOverloadResolver<CastType::nonAccurate>::createImpl(diagnostic);
|
|
case CastType::accurate:
|
|
return CastInternalOverloadResolver<CastType::accurate>::createImpl(diagnostic);
|
|
case CastType::accurateOrNull:
|
|
return CastInternalOverloadResolver<CastType::accurateOrNull>::createImpl(diagnostic);
|
|
}
|
|
}
|
|
|
|
|
|
REGISTER_FUNCTION(CastOverloadResolvers)
|
|
{
|
|
factory.registerFunction<CastInternalOverloadResolver<CastType::nonAccurate>>({}, FunctionFactory::CaseInsensitive);
|
|
/// Note: "internal" (not affected by null preserving setting) versions of accurate cast functions are unneeded.
|
|
|
|
factory.registerFunction<CastOverloadResolver<CastType::nonAccurate>>({}, FunctionFactory::CaseInsensitive);
|
|
factory.registerFunction<CastOverloadResolver<CastType::accurate>>();
|
|
factory.registerFunction<CastOverloadResolver<CastType::accurateOrNull>>();
|
|
}
|
|
|
|
}
|