Michael,
As far as I know, year 0 in MySQL is actually 1 AD. However, it doesn't
necessarily matter when that year is when you have the comparability of
the results.
What matters that this function in combination with its reverse,
FROM_DAYS, allows easily for one to compute things like:
- are both timestamps in the same day? TO_DAYS(tstamp1) = TO_DAYS(tstamp2)
- how many days are between the two dates? TO_DAYS(date1) - TO_DAYS(date2)
- what is the date if one adds X days to a specified date?
FROM_DAYS(TO_DAYS(date1) + X)
I'm not specifically in love with this function either, but what other
alternatives does Derby offer to make these computations?
Regards,
Robert
Michael Segel wrote:
On Friday 15 September 2006 7:15 am, Robert Enyedi wrote:
The TO_DAYS() function returns the number of days since year 0. Did
someone successfully port this functionality to Derby? Constructing a
Java function for this is not as straightforward as it looks.
Regards,
Robert
Why?
When was year 0?
Just because you see a function in MySQL, doesn't mean that its a good thing
or that it has value.
Everytime you "add" a function, you're increasing the footprint of Derby.
To some this isn't an issue. To others who wish to embed Derby within an
Applet/Servlet/whatever... This is not a good thing.
