Hi Peter, On Sat, 23 Jun 2018 at 17:47, PBKResearch <peter@pbkresearch.co.uk> wrote:
Hello All
I am experimenting with the version of OmniBase which Esteban Lorenzano posted a few days ago. With corrections posted by Matias Moretto, who is working on the same track, I have got the first five tests all green. On the sixth test, OmniBaseTest>>#testEquality, I have run into a strange failure. I donât know whether it shows that OmniBase is not recovering data correctly, or whether it is a feature of the way Date is implemented in Pharo. (I still have Dolphin 6 on my machine, including OmniBase, and there the same test passes.)
The test simply constructs a collection of various types of object, stores the whole collection on the database, retrieves it and compares each retrieved element with the corresponding element of the original collection. One element is obtained by evaluating âDate todayâ, and that is the one that fails. The test failure description is: âGot 23 June 2018 instead of 23 June 2018.â Using the inspector, I can see that the retrieved date differs from the original in that the instvar âstartâ has a Julian Day Number which is one greater, but seconds as zero instead of 82800 and an offset of zero instead of 1:00:00. In fact 82800 seconds is 23 hours, so all these add up to the same start time, just differently represented.
To get round the failure, I changed the constructor of the test collection to use âDate today printStringâ, which of course meant it worked perfectly. My worry is whether in some other context the change of the innards of the object might have an adverse effect. I donât understand why the Date constructor represents the start of today as 23 hours after 1 a.m. yesterday. Is the change something OmniBase has done in storing and retrieving, or is it due to the way the Date is reconstructed?
A Date in Pharo is a 24 hour period and thus the timezone is important, e.g. the start of 23 Jun in London is not the same as 23 Jun in Melbourne. If you want to compare the date using day / month / year and not as a 24 hour period, try using #equals: instead of #=. HTH, Alistair