Question

I am using PostgreSQL, I’ve one column named Result in Job table,
it contains values like 2/3, 1/3, 2/3.

For Example: Job table rows are:

job_id result
------ ------
1      2/3
2      1/3
3      2/3

I want to apply aggregate function on result column in such way that
I can get result like: 5/9

But Result is of text type column and we cannot directly apply sum/avg/min/max etc. function on that column.

Can anybody suggest any other approach to achieve that result using query itself?

All suggestions are appreciated.

Thanks.

Answer 1

SELECT SUM( dividend ) || '/' || SUM( divisor )
       AS FractionOfSums
     , AVG( dividend / divisor )        
       AS AverageOfFractions
FROM
  ( SELECT CAST(substr(result, 1, position('/' in result)-1 ) AS int)
           AS dividend
         , CAST(substr(result, position('/' in result)+1 ) AS int)
           AS divisor
    FROM rows
  ) AS division