Dear Christoph, perhaps you could try something like this example. Regards, BÃatrice
The table: ---------- # select * from test; date ------------ 2005-02-02 2005-03-05 2005-04-07 2005-05-02 (4 rows) The query ---------- SELECT (( select test1.date from test test1 where test1.date > test.date limit 1) - test.date ) AS result from test; t1.date > RESULT: ------- result -------- 31 33 25 Am Montag, den 21.03.2005, 10:54 +0100 schrieb Christoph Haller: > Octavio Alvarez wrote: > > > > Sorry, I tried to make my subject as good as possible. > > Ahem, what subject? > > > > I have a table where I store the dates in which I take out of my inventory > > (like "installation dates") > > > > table > > --------------- > > row_id SERIAL > > date DATE > > fk_item INTEGER > > > > and that's pretty much it. > > > > I want to have a query returning how long have been certain items lasting. > > > > Say I have: > > > > SELCT date FROM table WHERE fk_item = "INKJET_INK-BW" > > > > date > > ------------- > > 2005-02-02 > > 2005-03-05 > > 2005-04-07 > > 2005-05-02 > > > > I need something to calculate the intervals between those dates, like this: > > > > intervals (in days) > > -------------------- > > 31 > > 34 > > 25 > > > > So I can get the stddev and stuff from the "duration" of the items. > > > > I've been having a hard time with it. I'm trying NOT to program new > > functions. > > I cannot see how this could be achieved without the use of a function. > But if there is a way after all, I would be interested in learning it. > > > > Any help will be appreciated. > > > > --Octavio > > -- > > Regards, Christoph > > ---------------------------(end of broadcast)--------------------------- > TIP 3: if posting/reading through Usenet, please send an appropriate > subscribe-nomail command to [EMAIL PROTECTED] so that your > message can get through to the mailing list cleanly -- ---------------------------(end of broadcast)--------------------------- TIP 2: you can get off all lists at once with the unregister command (send "unregister YourEmailAddressHere" to [EMAIL PROTECTED])