A Common Table Expression makes perfect sense, to split a complex query into
smaller parts.
... but a Common Table Expression can only be used within the same SELECT
statement (incl. other CTEs and nested Sub-Selects).
... If the same CTE has to be used multiple times in different SELECT
Statements it makes more sense to create and use a (permanent) view.
Mit freundlichen Grüßen / Best regards
Birgitta Hauser
"Shoot for the moon, even if you miss, you'll land among the stars." (Les
Brown)
"If you think education is expensive, try ignorance." (Derek Bok)
"What is worse than training your staff and losing them? Not training them
and keeping them!"
?Train people well enough so they can leave, treat them well enough so they
don't want to.? (Richard Branson)
-----Original Message-----
From: MIDRANGE-L <midrange-l-bounces@xxxxxxxxxxxxxxxxxx> On Behalf Of Gad
Miron
Sent: Samstag, 12. Dezember 2020 11:55
To: midrange-l@xxxxxxxxxxxxxxxxxx
Subject: Re: Top 3 Reasons to Avoid Mixing SQL with QTEMP
Just seen Kent Milligan's excellent tips regarding the use of QTEMP with SQL
https://www.mcpressonline.com/analytics-cognitive/db2/techtip-top-3-reasons-
to-avoid-mixing-sql-with-qtemp
I wonder why not also use the With clause like
with tt as (select Cust_Id, sum(Ord_Amount) as OrdAmount from cust_ord group
by Cust_Id ) select tt.Cust_Id, Custfile.CustName, tt.OrdAmount from tt left
outer join Custfile on Custfile.Cust_Id = tt.Cust_Id What am I
missing/misunderstanding ?
TIA
Gad
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