RE: SETLL in SQL ?

From: Paul Raulerson

Joe - go read up on scrollable cursors. You are too intent on making the
point that you cannot do keyed reads.
What I reacted to was plain and simple your statement that you cannot move
backwards in a cursor without
closing and opening it.

I never said that, Paul. Please quote the post in which I said you could
not move backward. I just said that if your cursor starts at "G", then you
can't read the "F" records.

Like I said, go read up on scrollable cursors, they are available on
i5OS/OS400, at least from v5.2 up. You do not have to
close the cursor to position to the previous record, and the start of the
cursor, and the end, and any record in between,
or relative to your current position.

Paul, I wrote a training course on using JDBC, including cursors. I'm
pretty comfortable with how they work.

As for positioning within an SQL cursor by key- well - that seems more
than a little silly to me.

Well, that's your opinion. We all have one. In my experience, the ability
to order a large set of data and then move around in that subset quickly is
relatively important.

Real-world example: I might want to create a list of all memory chips,
sorted first by size then by price. I might want to jump back and forth
from the cheapest 512MB chips to the cheapest 1GB chips so I can decide
whether to use smaller chips and more slots, or larger chips and less slots.
If I can position by key (which I can do, by the way, using OPNQRYF), I can
use a single very fast I/O statement to jump back and forth. With SQL, I
have to rebuild the cursor each time.

Anyway, this part of the thread has devolved from how to do something (fact)
to whether you think it's silly (opinion), and at that point there are
diminishing returns.

Design the query
so your data comes back exactly in the order you need it, and with all the
data you need available for each record.

Yeah, see, here's the thing. Sometimes those pesky users just refuse to
conform to my idea of the order I need it, and sometimes they don't have the
time to wait for me to rebuild a cursor every time they want to look at
something.

If the task doesn't fit into SQL, then use something else, or redesign the
task.

Well, see, we agree after all. :)

Joe