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