how to get top 2 entries from each day in a week in MySql 5.5.34

Question

I have a MySQL table with columns TENANT_NAME , MAX_CALLS , and TIME_STAMP and there is no primary key , as per requirement for every hour we are inserting data and the same names can be repeated.

now I want to fetch like need to add group names and sum calls and fetch the top 2 entries per day in a week.

Ex: data insert at 22:49

TENANT_NAME,MAX_CALLS,TIME_STAMP
RS1, 20, 2022-12-07 22:49:17
RS2, 10, 2022-12-07 22:49:17
RS3, 2, 2022-12-07 22:49:17

in the next hour at 23:49

RS1, 15, 2022-12-07 23:49:17
RS2, 0, 2022-12-07 23:49:17
RS3, 20, 2022-12-07 23:49:17

like this, I have 1 year of data

now i want per day aggregation of groups of name 2 records of a week

like this

RS1, 35, MON
RS3, 22, MON... so on
RS4, 40, SUN
RS2, 35, SUN

I tried this query and I am able to group names and sum total calls, and display DAYNAME but I want the top 2 records per day of in a week.

select a.TENANT_NAME,SUM(a.MAX_CALLS),DAYNAME(a.TIME_STAMP) from TENANT_LIC_DISTRIBUTION AS a group by a.TENANT_NAME,day(a.TIME_STAMP) order by a.MAX_CALLS,a.TIME_STAMP;

RS1, 35, MON
RS3, 22, MON
RS2, 10, MON

RS3, 30, TUE
RS2, 20, TUE
RS1, 10, TUE.... so on
RS1, 20, SUN
RS2, 10, SUN
RS3, 1, SUN

and I want to fetch like this

RS1, 35, MON
RS3, 22, MON

RS3, 30, TUE
RS2, 20, TUE.... so on

RS1, 20, SUN
RS2, 10, SUN

please help me

Thanks

Answer 1

Try using a window function around your aggregation query to append row numbers, and then limit by row number. Here's one way.

WITH rank_tenant
AS (
    SELECT TENANT_NAME, 
    DAY, 
    CALLS, 
    row_number() OVER (
            PARTITION BY TENANT_NAME 
            ORDER BY CALLS DESC
            ) AS row_num
    FROM (select 
          TENANT_NAME,
          DAYNAME(TIME_STAMP) as DAY,
          SUM(MAX_CALLS) as CALLS
          from TENANT_LIC_DISTRIBUTION
          group by TENANT_NAME, DAY) as t1
    )
SELECT TENANT_NAME,
    DAY,
    CALLS
FROM rank_tenant
WHERE row_num <= 2;