Question

these are my tables

C_ID  USAGE B_ID
4     100   2
2     400   1
3     200   2
1     300   1

and

B_ID  ZONE_NAME
2     central
1     west

and here is my query,

select 
    sum(usage)  
from 
(
    select 
        usage_679.c_id,
        usage_679.b_id,usage_679.usage,
        zone_679.zone_name 
    from usage_679 inner join zone_679
        on zone_679.b_id = usage_679.b_id
)
where zone_name like 'w%';

problem is that it can print data related to west zone only.I want to print both zone name with total usage in respective zone.

expected output

zone_name  sum(usage)
1            700
2            300

Answer 1

Here is SQL FILLDE LINK FOR SAMPLE EXECUTION . You don’t need WHERE condition . You can achieve via GROUP BY

select 
    sum(usage),zone_name  
from 
(
    select 
        usage_679.c_id,
        usage_679.b_id,usage_679.usage,
        zone_679.zone_name 
    from usage_679 inner join zone_679
        on zone_679.b_id = usage_679.b_id
)
group by  zone_name

OUTPUT

| SUM(USAGE) | ZONE_NAME |
--------------------------
|        700 |      west |
|        300 |   central |

Even this would work: (No need of 2 SELECTS)

SELECT
    sum(USAGE),zone_name

    FROM usage_679 INNER JOIN zone_679
        ON zone_679.b_id = usage_679.b_id

GROUP BY  zone_name

OUTPUT:

| SUM(USAGE) | ZONE_NAME |
--------------------------
|        700 |      west |
|        300 |   central |