SQL Select记录的最大合计

Question

I need to select the "job role desc" of the maximum of the aggregates I have achieved. The table looks like follows.

[Job Role Description] |  [Number Of Placements]
------------------------------------------------
Training BI                     24
System Analyst                  23
Data Analyst                    24
Data consultant                 25
DB programmer                   24

The job_role_desc column is from another table joined by job_role_id . I used the following code to achieve this.

SELECT 
    job_role_dim.job_role_desc AS "Job Role Description" ,
    SUM(fact_accounts.no_of_placements) AS "Number Of Placements" 
FROM 
    fact_accounts 
INNER JOIN 
    job_role_dim ON job_role_dim.job_role_id =  fact_accounts.fk3_job_role_id 
GROUP BY 
    job_role_dim.job_role_desc

How can I modify the above code to only display the job_role_desc that has the maximum number of placements? Thank you for your help.

Answer 1

You can use row_number() or dense_rank() :

SELECT ja.*
FROM (SELECT j.job_role_desc AS "Job Role Description" ,   
             SUM(a.no_of_placements) AS "Number Of Placements",
             ROW_NUMBER() OVER (ORDER BY SUM(a.no_of_placements) DESC) as seqnum
      FROM fact_accounts a INNER JOIN
           job_role_dim j
           ON j.job_role_id = a.fk3_job_role_id
      GROUP BY j.job_role_desc
     ) ja
WHERE seqnum = 1;

If you want all versions with the maximum, then use dense_rank() or rank() .