--- Guy Fraser <guy@xxxxxxxxxxxx> wrote: > On Fri, 2005-23-09 at 09:48 -0700, Matthew Peter > wrote: > > > > --- Guy Fraser <guy@xxxxxxxxxxxx> wrote: > > > ...snip... > > > OK what I jotted down was totally wrong. > > > > > > This is slightly more correct : > > > > > > SELECT > > > array_upper(item,1) - array_lower(item,1) + 1 > as > > > elements > > > FROM > > > arraytest ; > > > > > > Without do a tonne of research, I can not refine > > > this to handle > > > all circumstances. > > > > > > Can someone point me to documentation that > explains > > > the function > > > better than : > > > > > > Dimensions can also be retrieved with > array_upper > > > and array_lower, which > > > return the upper and lower bound of a specified > > > array dimension, > > > respectively. > > > > > > The table "Table 9-36. array Functions" does not > > > explain how empty > > > and null arrays are handled either. > > > > > > How do array_upper() and array_lower() respond > to : > > > 1) NULL > > > 2) Empty Array > > > 3) Nonexistent requested dimension > > > > > > Also is there a function that specifies how many > > > dimensions the > > > array has? > > > > > > > That was exactly the answer I was looking for when > I > > posted the question. Now if there was a function > to > > delete a position in the array.... > > > > ie set array1 = array_delete_at(array1,5) where 5 > is > > the position to delete > > I hope someone else can answer that, the best I can > do > is provide a link to the docs : > > http://www.postgresql.org/docs/current/static/functions-array.html > > My best guess is that you need to "walk" the array > and > drop the element you don't want. The way I currently > > use arrays is I read the whole array into my > application > the modify the array then update the whole array. > > Unfortunately the arrays in PG are not associative > and the > elements must be sequential. I only use arrays in > limited > ways in PG because of earlier constraints, and have > not > needed to investigate the newer features. > > Good luck. > Ya. I read the docs and the (limitedly useful) Douglas book. I'm just playing around with arrays. Michael Fuhr suggested a intarray_del_elem() function. You may want to take a look at it too? MP __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to majordomo@xxxxxxxxxxxxxx so that your message can get through to the mailing list cleanly
