Literal actually does not have a exact data type, 1.23 can be both float or decimal, in order not to lose precision,we represent it as decimal internal.
Xiangwei Wei <[email protected]>于2020年3月5日 周四下午5:09写道： > Thank you for reply. What I want is a getValue() method which returns > exactly the value of literal based on its type. You are right that I can > use literal.getValueAs(Double.class) to get a Double value, but maybe it's > better to provide a method like what I say. What do you think? > > Julian Hyde <[email protected]> 于2020年3月5日周四 下午2:20写道： > > > As the java doc says, RexLiteral.getValue2 returns values in the form > that > > the calculator builder needs them. That may not be the form that you need > > them. In which case, don’t use that method. > > > > If you want a Double, have you tried literal.getValueAs(Double.class)? > > > > (We don’t tend to use Float and Double much because when we’re compiling > > queries we can’t afford any loss of precision. If the user typed 1.1 we > > want exactly 1.1, whereas Decimal might be something like > 1.000000000987.) > > > > > On Mar 4, 2020, at 9:43 PM, Xiangwei Wei <[email protected]> > wrote: > > > > > > In RexLiteral.getValue2(), it treats Decimal just by `return > > > getValueAs(Long.class);`. > > > In this instance, we can't get a correct double/float value because > it's > > > considered as Decimal type here. Is this a problem or is there a reason > > > here? > > > > > > -- > > > Best, > > > Xiangwei Wei > > > > > > -- > Best, > Xiangwei Wei >
