RE: SETLL in SQL ?

(Interesting- this mail was refused delivery in queue yesterday! Was
something going on with the ListServ or have I just been blacklisted? -Paul
:) :) :)



Well, if you insist:

From: Michael_Schutte@xxxxxxxxxxxx

What do you mean? the program I pulled it from has been in use since

1998.

Page Up/Page Down works properly even after end of cursor is reached.

The fetch relative is only executed when the page up is pressed... on

a page down, a regular fetch is executed without positioning.

If you initially created the cursor with a "position to" (in SQL terms,

a

WHERE clause such as WHERE NAME >= "G"), and then immediately try to roll
back >(to get the last page of names starting with "F") you cannot use the
RELATIVE technique.

If your cursor contains ALL the records in the file, then you can

certainly

roll through them, but typically the user wants to position to a starting

key value, which requires the WHERE clause above (which corresponds to

a

SETLL in RPG). Once you've done that, there's no way to use that cursor to
get >previous records.

Joe

And to be fair the question I posted was:

Not to be argumentive either, but are you saying that DB/2 on a 400

doesn't

support scrollable cursors? I would be rather surprised to find that is

true.

And scrollable cursors allow you to position either by sequence or by

reference.



Which was tied to a later message in the exchange and could have been
confusing.

(I tend to read through them all before I post or ask a question.)





So basically, what to me looked like and was intended as a question could
have looked to you like some kind of snarly answer.

But here is my take- having been in the electronic communications game now
since they opened my Arpanet account a very long time ago - it is easy to
misinterpret the context and tone of what someone is saying, especially if
anyone is the least bit careless in how they phrase or reference something.
(I am a bit guilty of that here, since the question I put out was sort of
tangential to the conversation.) Still- it *was* just a question, one I
figured you would know right off the top of your head without the need to go
look it up. Same as I could do had that been a reference to Mainframe DB/2.




It takes a lot of effort to "listen" to what is written electronically, and
one must develop the habit of thinking through what they think they heard.



By the way, in the quoted original message above, you could simply ensure
the cursor is ordered, look at the number of records retrieved, and then
perform a fairly efficient binary search - which is something *I* tend to do
when I have that particular problem. They can be coded to operate very fast
on results up to a few hundred thousand records. Then again, I would
probably just use files to do this on the 400. <shrug>

-----Original Message-----

From: rpg400-l-bounces@xxxxxxxxxxxx [mailto:rpg400-l-

bounces@xxxxxxxxxxxx] On Behalf Of Joe Pluta

Sent: Saturday, October 13, 2007 11:42 AM

To: 'RPG programming on the AS400 / iSeries'

Subject: RE: SETLL in SQL ?

From: Paul Raulerson

Or you can design the application differently. Or use two queries,

or table up the starting records of interest, or... any of a lot of

different techniques. This is pretty

much

a strawman argument, because

it is an argument built only to prove your point... <grin>

Gotta call bull**** on this, Paul. I'm not trying to prove anything,

only giving a real world example of something I do all the time, every

day, that requires positioning by key within an already-created view.

You want to call it a strawman, that's fine, but you're misusing the

term and avoiding the issue.

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.

That's mostly because you have a bit of attitude if anyone appears

to

be

challenging you, even when they are not. Read what I wrote - I

really

did

just ask you a question. You layered on the attitude mate. ;)

<laughing> *I* have attitude?!?!!? Oh, golly, please read the thread

and see who uses words like "silly" to describe the other person's

opinion.

Or

who told who to "go read up". Paul, I daresay you are one of the few

people on the list whose attitude meter can match mine. <grin>

What I asked was if the 400 supported scrollable cursors - which

once

I

spent the 20 minutes to dig in the docs, it does.

You didn't actually ask, you said "are you saying that..." which

typically denotes more of a rhetorical question. More importantly I

didn't find it necessary to answer it since scrollable cursors do not

allow you to position by key, which was the only point I initially

made. I never said you couldn't move backwards, and again, I ask you

to find the post where I said that, since it's the basis of your

entire argument.

To quote me: "You cannot position a cursor by key. This is true in

all dialects of SQL."

Scrollable cursors offer several possible solutions to the problem

that you appear to have not considered.

Actually, I considered all of the options if you read my posts,

including what I consider the best solution, which is Walden's

dual-cursor approach, although it is still, in my opinion, not as good

as a simple ISAM key.

And by the way, the phrase "you appear to not have considered" is not

only simply wrong factually, it is in my opinion dripping with

attitude because it has lots of implied negative judgment in it.

Maybe you don't see it that way, and it's simply our different uses of

the English language that are putting us a bit at odds.

Well, see, we agree after all. :)

As is usually the case when you get down to the hard facts.

Yup.

And let me reiterate the FACT:

"You cannot position a cursor by key. This is true in all dialects of

SQL."

Is this correct or not?

It it's incorrect, I apologize, if it's correct, well, I'll let you

decide whether you want to do the civil thing.

Joe

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