Re: "Position To:" Design Challenge with SQL -- WEB400

To expand...

The use case for doing a "Position to" and rolling backward is really
pretty limited. In fact, as I see it, it's not really a use case at all.
Instead it's a short cut the user has come up with to deal with the
limitations of RLA and "Position to"..

I need to get to Zimmerman in Michigan....my screen only allows me to
position to a certain state or a certain last name. Rather than pageing
through the 1000 people in Michigan or the 400 Zimmermans in the country, I
can position to Minnesota and roll back 1 screen to Zimmerman in MI.

HTH,
Charles

On Thu, Dec 12, 2013 at 1:32 PM, Charles Wilt <charles.wilt@xxxxxxxxx>wrote:

Don't do it.

The "Position to" paridgm is really tied to RLA.

SQL being set based is better suited to "Filtering" or "subsetting". And
the fact is with SQL you can offer lots more filtering options including
wildcards that perform well than you ever could with RLA.

That being said, this has been discussed before. So a search of the
archives is in order. But in short, the cleanest solution IMHO is to open
two cursors:
select *
from tbl
where key >= :PosTo

select *
from tbl
where key <:PosTo

End you hit the top of the forward scrolling cursor, you switch to the
other.

But again, IMHO, by sticking with the "Position to" you are losing out on
the benefits SQL can provide.

Charles

Charles

On Thu, Dec 12, 2013 at 12:24 PM, Holm, Paul <pholm@xxxxxxxxxxxxxxxxx>wrote:

All,

I'm interested if anyone has worked on a design to enable "position to"
type of web searches. Any insight or gotchas would be appreciated. We
have a series of requirements that require a web search but with the
ability to scroll up or down from that key value position. I know RPG
does
this but we need an SQL based solution.

To further explain the need...Assume you have a database table of all
people living in the US. We want to be able to search based on a number
of
criteria such as "state". So I search for "MINNESOTA" and I'm presented
with a list/subfile of people living in MN. Example SQL: SELECT * FROM
US_PEOPLE where STATE = "MN" order by STATE, LASTNAME

Now they want to "scroll up" in the list which should then display people
in "MICHIGAN" . The issue is "MICHIGAN" is not in my result set. If I
scrolled down thru MN then I would see "Mississippi".

We are dealing with large tables so we need to make the searches perform.
We also obviously are looking for a "generic" design so it can be used
for
numerous inquiry applications... Anyone have experience?

Thanks in advance, Paul Holm

www.planetjavainc.com
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