How to make sum of two rows in a table?

Question

The table has the values like,

   group_name    group_id    parent_group_id     amount

     One           69             10              1000
     Two           70             11              500
    Three          71             69              700

Here I need to make sum of the values in amount column if the group id = 69 matches with the parent_group_id = 69 for which I have tried with

SUM(CASE WHEN fee_groups.groups_id = fee_groups.parent_fee_groups_id 
            THEN amount 
         ELSE 0 
     END) AS total

But above line doing nothing for me. If I am wrong with it then kindly help me to achieve the following result,

   group_name    group_id    parent_group_id     amount

     One           69             10              1700
     Two           70             11              500  

Here the group_id and parent_group_id make a relationship, if there is a match from any of the parent_group_id with group_id then both are comes under single group and hence I need to sum both the values.

Answer 1

It doesn't make sense to me to include group_id and parent_group_id given what you want to do. You also don't explain what happens to the "71".

select min(group_name) as group_name,
       sum(amount)
from t
group by (case when 69 not in (group_id, parent_group_id) then group_name end);

This will combine the groups that share "69" and keep the others separate.

Answer 2

Try this solution:

SELECT t1.group_name, t1.group_id, t1.parent_group_id, 
      (t1.amount + IFNULL(t2.amount,0)) Amount
FROM Table1 t1
LEFT JOIN Table1 t2 
ON t1.group_id = t2.parent_group_id 
OR t2.group_id = t1.parent_group_id
WHERE t1.group_name < t2.group_name OR t2.group_name IS NULL
GROUP BY t1.group_name, t1.group_id, t1.parent_group_id

OUTPUT:

group_name  group_id    parent_group_id   Amount
One         69           10               1700
Two         70           11               500

Answer 3

Try this

SELECT 
group_name,group_id,parent_group_id,
(CASE WHEN group_id = 69 THEN 
(amount+(SELECT amount FROM table1 WHERE parent_group_id = 69)) 
ELSE amount END) as new_amount 
FROM Table1 WHERE parent_group_id !=69;

Answer 4

do the execute below query or this link

sqlfiddle

 select t.group_name,t.group_id,t.parent_group_id,
           (case when t.group_id = t1.parent_group_id then t1.amount + t.amount else t.amount end)
    from t 
    left join t as t1 on t.group_id = t1.parent_group_id
where t.group_id <>71