ClickHouse/dbms/src/Functions/extractTimeZoneFromFunctionArguments.cpp
2018-09-26 03:31:40 +03:00

70 lines
2.1 KiB
C++

#include <Functions/extractTimeZoneFromFunctionArguments.h>
#include <Functions/FunctionHelpers.h>
#include <Core/Block.h>
#include <DataTypes/DataTypeDateTime.h>
#include <Columns/ColumnString.h>
#include <common/DateLUT.h>
namespace DB
{
namespace ErrorCodes
{
extern const int ILLEGAL_COLUMN;
}
static std::string extractTimeZoneNameFromColumn(const IColumn & column)
{
const ColumnConst * time_zone_column = checkAndGetColumnConst<ColumnString>(&column);
if (!time_zone_column)
throw Exception("Illegal column " + column.getName()
+ " of time zone argument of function, must be constant string",
ErrorCodes::ILLEGAL_COLUMN);
return time_zone_column->getValue<String>();
}
std::string extractTimeZoneNameFromFunctionArguments(const ColumnsWithTypeAndName & arguments, size_t time_zone_arg_num, size_t datetime_arg_num)
{
/// Explicit time zone may be passed in last argument.
if (arguments.size() == time_zone_arg_num + 1 && arguments[time_zone_arg_num].column)
{
return extractTimeZoneNameFromColumn(*arguments[time_zone_arg_num].column);
}
else
{
if (!arguments.size())
return {};
/// If time zone is attached to an argument of type DateTime.
if (const DataTypeDateTime * type = checkAndGetDataType<DataTypeDateTime>(arguments[datetime_arg_num].type.get()))
return type->getTimeZone().getTimeZone();
return {};
}
}
const DateLUTImpl & extractTimeZoneFromFunctionArguments(Block & block, const ColumnNumbers & arguments, size_t time_zone_arg_num, size_t datetime_arg_num)
{
if (arguments.size() == time_zone_arg_num + 1)
return DateLUT::instance(extractTimeZoneNameFromColumn(*block.getByPosition(arguments[time_zone_arg_num]).column));
else
{
if (!arguments.size())
return DateLUT::instance();
/// If time zone is attached to an argument of type DateTime.
if (const DataTypeDateTime * type = checkAndGetDataType<DataTypeDateTime>(block.getByPosition(arguments[datetime_arg_num]).type.get()))
return type->getTimeZone();
return DateLUT::instance();
}
}
}