sum price of childs in other table mysql

Question

I have two table one store data child and parent hierarchy and other paths and descendant

+----------+------------+-----------+
| userid   |    parent  |    price  |
+----------+------------+------------
| 1        |    null    |      20   | 
| 2        |      1     |      20   | 
| 3        |      1     |      20   | 
| 4        |      2     |      20   | 
| 5        |      2     |      20   | 
| 6        |      3     |      20   | 
| 7        |      4     |      20   | 
+----------+------------+-----------+

I need to get all userid with parent 1 then get descendant in other table and group by userid sum prices

+-------------+---------------+-------------+
| ancestor_id | descendant_id | path_length |
+-------------+---------------+-------------+
|           1 |             1 |           0 |
|           1 |             2 |           1 |
|           1 |             3 |           1 |
|           1 |             4 |           2 |
|           1 |             5 |           2 |
|           1 |             6 |           2 |
|           1 |             7 |           3 |
|           2 |             2 |           0 |
|           2 |             4 |           1 |
|           2 |             5 |           1 |
|           2 |             7 |           2 |
|           3 |             3 |           0 |
|           3 |             6 |           1 |
|           4 |             4 |           0 |
|           4 |             7 |           1 |
|           5 |             5 |           0 |
|           6 |             6 |           0 |
|           7 |             7 |           0 |
+-------------+---------------+-------------+

I have query it sum all childs together

select 
sum(b.price)

from webineh_prefix_nodes_paths_tmp a

    join webineh_prefix_nodes_tmp b on (b.userid = a.descendant_id)

where a.ancestor_id = 1 

this work fine but total sum parent 1

I need to show bellow result for child direct (2,3)

 +----------+------------+-
    | userid   |    total   |
    +----------+------------+
    | 2        |    80      |
    | 3        |    40      |
    +----------+------------+

also in create sqlfiddle my question http://sqlfiddle.com/#!9/9415ed/2

Answer 1

try this

select sum(b.price) from webineh_prefix_nodes_paths_tmp a join webineh_prefix_nodes_tmp b on (b.userid = a.descendant_id) where a.ancestor_id in ( 1,2,3) GROUP by ancestor_id

Answer 2

Try this;)

select ancestor_id as userid, sum(b.price) as total
from webineh_prefix_nodes_paths_tmp a 
join webineh_prefix_nodes_tmp b 
on b.userid = a.descendant_id
where a.ancestor_id in (select userid from webineh_prefix_nodes_tmp where parent = 1)
group by ancestor_id

SQLFiddle Demo

Edited

select ancestor_id as userid, sum(b.price) as total
from webineh_prefix_nodes_paths_tmp a 
join webineh_prefix_nodes_tmp b 
on b.userid = a.descendant_id
inner join webineh_prefix_nodes_tmp c
on a.ancestor_id = c.userid
and c.parent = 1
group by ancestor_id

SQLFiddle Demo