Update records with Count() function

Question

Update records with Count() function

DerbyNeal

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Points: 3854
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July 26, 2012 at 5:29 am

#278496

Hi all,
My SQL 'Table1' needs an update to a single column 'STCount'. The update needs to be applied
grouped by 'Sales_Resp', 'Sales_Order', 'Sales_Type'.
So,
'Sales_Resp', 'Sales_Order', 'Sales_Type', 'STCount'
TWells, 123, 4, 0
TWells, 123, 4, 0
TWells, 123, 4, 0
TWells, 125, 4, 0
TWells, 125, 4, 0
ABaker, 129, 4, 0
ABaker, 129, 4, 0
ABaker, 130, 9, 0
ABaker, 130, 9, 0
ABaker, 130, 9, 0
ABaker, 130, 9, 0
Should become...
'Sales_Resp', 'Sales_Order', 'Sales_Type', 'STCount'
TWells, 123, 4, 3
TWells, 123, 4, 3
TWells, 123, 4, 3
TWells, 125, 4, 2
TWells, 125, 4, 2
ABaker, 129, 4, 2
ABaker, 129, 4, 2
ABaker, 130, 9, 4
ABaker, 130, 9, 4
ABaker, 130, 9, 4
ABaker, 130, 9, 4
Can anyone help please?
Thanks in advance,

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Phil Parkin SSC Guru Points: 246756 More actions · Answer 1

DerbyNeal (7/26/2012)
Hi all,
My SQL 'Table1' needs an update to a single column 'STCount'. The update needs to be applied
grouped by 'Sales_Resp', 'Sales_Order', 'Sales_Type'.
So,
'Sales_Resp', 'Sales_Order', 'Sales_Type', 'STCount'
TWells, 123, 4, 0
TWells, 123, 4, 0
TWells, 123, 4, 0
TWells, 125, 4, 0
TWells, 125, 4, 0
ABaker, 129, 4, 0
ABaker, 129, 4, 0
ABaker, 130, 9, 0
ABaker, 130, 9, 0
ABaker, 130, 9, 0
ABaker, 130, 9, 0
Should become...
'Sales_Resp', 'Sales_Order', 'Sales_Type', 'STCount'
TWells, 123, 4, 3
TWells, 123, 4, 3
TWells, 123, 4, 3
TWells, 125, 4, 2
TWells, 125, 4, 2
ABaker, 129, 4, 2
ABaker, 129, 4, 2
ABaker, 130, 9, 4
ABaker, 130, 9, 4
ABaker, 130, 9, 4
ABaker, 130, 9, 4
Can anyone help please?
Thanks in advance,

As this is dynamic, calculated info, I'd suggest using a view for this rather than persisting the info as part of the table - it's not a good design.

But something like this should do it:

;with Counts as (select Sales_Resp, Sales_Order, Sales_Type, count(1) [Count] group by Sales_Resp, Sales_Order, Sales_Type)

update t

set STCount = Counts.Count

from Table1 t join Counts on t.Sales_Resp = Counts.Sales_Resp and t.Sales_Order = Counts.Sales_Order and t.Sales_Type = Counts.Sales_Type

If you haven't even tried to resolve your issue, please don't expect the hard-working volunteers here to waste their time providing links to answers which you could easily have found yourself.

ChrisM@Work SSC Guru Points: 186127 More actions · Answer 2

DerbyNeal (7/26/2012)
Hi all,
My SQL 'Table1' needs an update to a single column 'STCount'. The update needs to be applied
grouped by 'Sales_Resp', 'Sales_Order', 'Sales_Type'.

I'd agree with Phil - it's not worth persisting as it's so trivial to calculate on-the-fly:

SELECT

Sales_Resp,

Sales_Order,

Sales_Type,

STCount = COUNT(*) OVER (PARTITION BY Sales_Resp, Sales_Order, Sales_Type)

FROM ...

^{“Write the query the simplest way. If through testing it becomes clear that the performance is inadequate, consider alternative query forms.” - Gail Shaw}

For fast, accurate and documented assistance in answering your questions, please read this article.
Understanding and using APPLY, (I) and (II) Paul White
Hidden RBAR: Triangular Joins / The "Numbers" or "Tally" Table: What it is and how it replaces a loop Jeff Moden