Re: getting count for a specific querry

On Apr 9, 2005 10:00 AM, John DeSoi <desoi(at)pgedit(dot)com> wrote:
>
>
> On Apr 8, 2005, at 3:37 PM, Joel Fradkin wrote:
>
> > I don't think my clients would like me to aprox as it is a count of
> > their
> > records. What I plan on doing assuming I can get all my other problems
> > fixed
> > (as mentioned I am going to try and get paid help to see if I goofed
> > it up
> > some where) is make the count a button, so they don't wait everytime,
> > but
> > can choose to wait if need be, maybe I can store the last count with a
> > count
> > on day for the generic search it defaults to, and just have them do a
> > count
> > on demand if they have a specific query. Our screens have several
> > criteria
> > fields in each application.
>
> Here is an interface idea I'm working on for displaying query results
> in PostgreSQL. Maybe it will work for you if your connection method
> does not prevent you from using cursors. I create a cursor an then
> fetch the first 1000 rows. The status display has 4 paging buttons,
> something like this:
>
> |< < rows 1 - 1000 of ? > >|
>
> The user can hit the "next" button to get the next 1000. If less than
> 1000 are fetched the ? is replaced with the actual count. They can
> press the "last" button to move to the end of the cursor and get the
> actual count if they need it. So here the initial query should be fast,
> the user can get the count if they need it, and you don't have to
> re-query using limit and offset.
>
> The problem I'm looking into now (which I just posted on the general
> list) is I don't see a way to get the table and column information from
> a cursor. If I fetch from a cursor, the table OID and column number
> values are 0 in the row description. If I execute the same query
> directly without a cursor, the row description has the correct values
> for table OID and column number.
>
> John DeSoi, Ph.D.
> http://pgedit.com/
> Power Tools for PostgreSQL

Oracle Forms uses a similar method as you described and it works just fine.
It will say Record 1 of ?(But I think the developer can set the amount of
records cached so that if you set it to 10 and queried 5 records it would
say record 1 of 5 because it would be under the cache amount.) Forms also
offers a button that say get hit count. So if you really need to know the
record count you can get it without moving off the current record.