CODEWITHSUNDEEP
sql-servert-sqlssmsaggregate-functions
Calflamesfann
Calflamesfann

Reputation: 143

Custom aggregations in SQL

I have a table named industry. There are 6 fields. The schema is given below.

In this case, am needing to perform custom aggregations. There are 22 areas in the database. Two custom aggregations need to be made:

  1. Areas 1-17 need to be combined into a new area with value 00.
  2. Areas 20 and 21 need to be made into another with code value 99.

Next is my attempt at an overall framework for this. I am assuming that creating a new table is the simplest way to accopmlish this. At the bottom is a very short example of the intended result. 

 create table industry2
 (
 year char(4),
 qtr char(2),
 area char(6),
 industry char(3),
 ownership char(2),
 employment numeric(8,0)
 );

 INSERT INTO Industry2
 (year, qtr, area, industry, ownership, employment)
 SELECT year, qtr, area, (select sum (employment) from dbo.industry where area 
 = '01' or area = '02' and so on):

 2017    01    01   123000    1    456
 2017    01    02   123000    1    101
 2017    01    03   123000    1    103
 2017    01    01   134000    1      6
 2017    01    02   134000    1      7
 2017    01    03   134000    1     12
 2017    01    09   134000    1      1
 2017    01    01   144000    1     14
 2017    01    20   134000    1      7
 2017    01    21   134000    1      8

Intended result

 2017   01     00   123000    1    660
 2017   01     00   134000    1     26
 2017   01     00   144000    1     14
 2017   01     99   134000    1     15

Upvotes: 1

Views: 83

Answers (1)

Andrea
Andrea

Reputation: 12415

You can define your custom GROUP BY clause with a CASE WHEN statement:

select  [year], 
        [qtr],
        case when [area] in('20','21') then '99' when [area] between 1 and 17 then '00' end as [area], 
        [industry], 
        [ownership], 
        sum([employment]) as [employment_sum] 
from industry2 
group by  
    [year], 
    [qtr], 
    case when [area] in('20','21') then '99' when [area] between 1 and 17 then '00' end, 
    [industry], 
    [ownership]

Result:

enter image description here

Upvotes: 2

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