How to calculate the sum of multiple columns and enter it into a single col

Question

I have a table tab_contributions which has the following columns:
Emp_code Current_month(format: yyyymm) Contribution_amt
Sample entry:
Emp_code Current_month Contribution_amt
100 200910 100
100 200911 100
100 200912 100
100 200912 100
100 201001 100
100 201002 100
100 201003 100
Desired output: Table_result
Emp_code Years Contribution_amt
100 2009-2010 700
Also, the years duration should be of only one year. For eg: 2008-2009, 2009-2010 etc.
Edited by: user9027633 on Feb 26, 2010 12:34 AM

Answer 1

Select Emp_code, min(substr(Current_month,1,4))||'-'||max(substr(Current_month,1,4)) period, sum(Contribution_amt) amount
from mytable
group by Emp_code;
SQL> with mytable as (
  2  select 100 Emp_code, 200910 Current_month, 100 Contribution_amt from dual union all
  3  select 100, 200911, 100 from dual union all
  4  select 100, 200912, 100 from dual union all
  5  select 100, 200912, 100 from dual union all
  6  select 100, 201001, 100 from dual union all
  7  select 100, 201002, 100 from dual union all
  8  select 100, 201003, 100 from dual)
  9  Select Emp_code,
10         min(substr(Current_month,1,4))||'-'||
11         max(substr(Current_month,1,4)) period,
12         sum(Contribution_amt) amount
13  from mytable
14  group by Emp_code;
  EMP_CODE PERIOD        AMOUNT
       100 2009-2010        700Max
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Edited by: Massimo Ruocchio on Feb 26, 2010 9:11 AM
Added example