public long ToInt64()
{
if (IsNull)
throw new SqlNullValueException();
long ret = _value / (s_lTickBase / 10);
bool fPositive = (ret >= 0);
long remainder = ret % 10;
ret = ret / 10;
if (remainder >= 5)
{
if (fPositive)
ret++;
else
ret--;
}
return ret;
}