Function convertFieldToTypeImpl

src/Interpreters/convertFieldToType.cpp:171–522

Field convertFieldToTypeImpl(const Field & src, const IDataType & type, const IDataType * from_type_hint)
{
    if (from_type_hint && from_type_hint->equals(type))
    {
        return src;
    }

    WhichDataType which_type(type);
    WhichDataType which_from_type;

    if (from_type_hint)
    {
        which_from_type = WhichDataType(*from_type_hint);
    }

    /// Conversion between Date and DateTime and vice versa.
    if (which_type.isDate() && which_from_type.isDateTime())
    {
        return static_cast<UInt16>(static_cast<const DataTypeDateTime &>(*from_type_hint).getTimeZone().toDayNum(src.get<UInt64>()).toUnderType());
    }
    else if (which_type.isDate32() && which_from_type.isDateTime())
    {
        return static_cast<Int32>(static_cast<const DataTypeDateTime &>(*from_type_hint).getTimeZone().toDayNum(src.get<UInt64>()).toUnderType());
    }
    else if (which_type.isDateTime() && which_from_type.isDate())
    {
        return static_cast<const DataTypeDateTime &>(type).getTimeZone().fromDayNum(DayNum(src.get<UInt64>()));
    }
    else if (which_type.isDateTime() && which_from_type.isDate32())
    {
        return static_cast<const DataTypeDateTime &>(type).getTimeZone().fromDayNum(DayNum(src.get<Int32>()));
    }
    else if (which_type.isDateTime64() && which_from_type.isDate())
    {
        const auto & date_time64_type = static_cast<const DataTypeDateTime64 &>(type);
        const auto value = date_time64_type.getTimeZone().fromDayNum(DayNum(src.get<UInt16>()));
        return DecimalField(
            DecimalUtils::decimalFromComponentsWithMultiplier<DateTime64>(value, 0, date_time64_type.getScaleMultiplier()),
            date_time64_type.getScale());
    }
    else if (which_type.isDateTime64() && which_from_type.isDate32())
    {
        const auto & date_time64_type = static_cast<const DataTypeDateTime64 &>(type);
        const auto value = date_time64_type.getTimeZone().fromDayNum(ExtendedDayNum(static_cast<Int32>(src.get<Int32>())));
        return DecimalField(
            DecimalUtils::decimalFromComponentsWithMultiplier<DateTime64>(value, 0, date_time64_type.getScaleMultiplier()),
            date_time64_type.getScale());
    }
    else if (type.isValueRepresentedByNumber() && src.getType() != Field::Types::String)
    {
        if (which_type.isUInt8()) return convertNumericType<UInt8>(src, type);
        if (which_type.isUInt16()) return convertNumericType<UInt16>(src, type);
        if (which_type.isUInt32()) return convertNumericType<UInt32>(src, type);
        if (which_type.isUInt64()) return convertNumericType<UInt64>(src, type);
        if (which_type.isUInt128()) return convertNumericType<UInt128>(src, type);
        if (which_type.isUInt256()) return convertNumericType<UInt256>(src, type);
        if (which_type.isInt8()) return convertNumericType<Int8>(src, type);
        if (which_type.isInt16()) return convertNumericType<Int16>(src, type);