This is not recommended as performance may be poor.
Imagine if there are 10 million rows on the table and no suitable index for the WHERE clause.
This solution may result in all 10 million records being read just to determine if 1 row exists (which may be the first row read) !
________________________________________
From: rpg400-l-bounces@xxxxxxxxxxxx [rpg400-l-bounces@xxxxxxxxxxxx] on behalf of Alan Shore [ashore@xxxxxxxx]
Sent: 19 December 2012 20:39
To: RPG programming on the IBM i / System i
Subject: RE: SQL Question
Another way is
Select count(*) from file where value = whatever
Alan Shore
Programmer/Analyst, Direct Response
E:AShore@xxxxxxxx
P:(631) 200-5019
C:(631) 880-8640
"If you're going through Hell, keep going" - Winston Churchill
-----Original Message-----
From: Alan Shore
Sent: Wednesday, December 19, 2012 3:38 PM
To: RPG programming on the IBM i / System i
Subject: RE: SQL Question
Select * from file where value = whatever
Alan Shore
Programmer/Analyst, Direct Response
E:AShore@xxxxxxxx
P:(631) 200-5019
C:(631) 880-8640
"If you're going through Hell, keep going" - Winston Churchill
-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx [mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Jeff Young
Sent: Wednesday, December 19, 2012 3:29 PM
To: RPG programming on the IBM i / System i
Subject: SQL Question
All,
I am having a brain freeze (aka senior moment).
I want to use SQL to determine if a record exists in a file for a given value.
There will be either only 1 record in the file for the value, or it will not exist.
Thanks,
--
Jeff Young
Sr. Programmer Analyst
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