ClickHouse/dbms/src/AggregateFunctions/AggregateFunctionAvg.cpp
2019-12-18 13:02:04 +03:00

49 lines
1.5 KiB
C++

#include <AggregateFunctions/AggregateFunctionFactory.h>
#include <AggregateFunctions/AggregateFunctionAvg.h>
#include <AggregateFunctions/Helpers.h>
#include <AggregateFunctions/FactoryHelpers.h>
#include "registerAggregateFunctions.h"
namespace DB
{
namespace
{
template <typename T>
struct Avg
{
using FieldType = std::conditional_t<IsDecimalNumber<T>, Decimal128, NearestFieldType<T>>;
using Function = AggregateFunctionAvg<T, AggregateFunctionAvgData<FieldType, UInt64>>;
};
template <typename T>
using AggregateFuncAvg = typename Avg<T>::Function;
AggregateFunctionPtr createAggregateFunctionAvg(const std::string & name, const DataTypes & argument_types, const Array & parameters)
{
assertNoParameters(name, parameters);
assertUnary(name, argument_types);
AggregateFunctionPtr res;
DataTypePtr data_type = argument_types[0];
if (isDecimal(data_type))
res.reset(createWithDecimalType<AggregateFuncAvg>(*data_type, *data_type, argument_types));
else
res.reset(createWithNumericType<AggregateFuncAvg>(*data_type, argument_types));
if (!res)
throw Exception("Illegal type " + argument_types[0]->getName() + " of argument for aggregate function " + name,
ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
return res;
}
}
void registerAggregateFunctionAvg(AggregateFunctionFactory & factory)
{
factory.registerFunction("avg", createAggregateFunctionAvg, AggregateFunctionFactory::CaseInsensitive);
}
}