>>Hi all,
>>
>>What is the advantage when we allowing Null data type to each data field?
>>
>Aston,
>
>Null's are usefull when value in a field can be unknown. It mostly used with datetime data type to represent unknown or not entered yet value. I tend to use them only if I've to because they can be a pain to work with.
They're quite useful if you are working with data that will be used for any statistical purposes -- means, medians, standard deviations, and the like. In that case NULL can mean "not applicable" and these values are left out of the equations. When I worked on statistical apps in FP 1.* and 2.* I always had to write complicated procedures to duplicate what I can now accomplish with standard function calls.
The whole problem with the world is that fools and fanatics are always so certain of themselves, but wiser people so full of doubts. - Bertrand Russell
