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Re: SQL: how to farm journal: select only oldest and newest record for each cust #



fixed

Yeah, once you have the outfile, you can use correlated table expressions - the "with xx as select..." kind of thing to essentially get a couple views over the data - one view could have the minima, the other the maxima - something like that.

I don't know the data well enough - just throwing out concepts. The CTEs can give you something like WHERE sometimestamp = (select min(jotimestamp) from such and such CTE)

I know this is sketchy - but it should all be doable - Charles already got you started, probably.

Vern

On 9/28/2012 1:54 PM, Stone, Joel wrote:
Thanks Vern

Your response sounds like I could select one cust change pair of journal records.

Can the first select get ALL the cust recs with the lowest time-stamp?

For example, cust A has 10 journal records and cust B has 2 journal records.

Can I build an SQL stmt that will return a min for cust A and also a min for cust B - in one SQL stmt?



-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Vernon Hamberg
Sent: Friday, September 28, 2012 12:09 PM
To: Midrange Systems Technical Discussion
Subject: Re: SQL: how to farm journal: select only oldest and newest record for each cust #

Hi Joel

A quick thought - use a UNION SELECT. This assumes you have some
criteria for the particular set of records - the first SELECT would get
the record with some minimum timestamp, the second SELECT would get the
record with some maximum timestamp.

I'm just flying off the cuff with this - not sure it'd work at all -
depends on how the data comes out. It'll work in a general sense, though.

Vern

On 9/28/2012 10:32 AM, Stone, Joel wrote:
Is it possible (and simple) to select only two records from the journal - for each file-RRN combination?


Example:

Users make 20 changes throughout the day to CUST #123 record.

I want to select only the first "before" image and the last "after" image for that particular cust (and all other custs).

Can SQL select these with a simple statement?

Or is this best done in an HLL pgm?


Thanks



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