Combining tables

Question

Hi guys,
I'm having two separate tables
table A with column 'CUST_ID' and column 'COUNT'
table B with column 'CUST_ID' and column 'COUNT'
I'm facing problem in combining both table by adding the col 'COUNT' from two different table if the 'CUST_ID' is the same.
e.g.
I would like to add up the COUNT and combine the CUST_ID into one:
TABLE A
CUST _ID     COUNT
AB_123 58
TABLE B
CUST _ID     COUNT
AB_123 2
RESULT:
CUST _ID     COUNT
AB_123 60
Pls advice
thanks.
Ivan Baros

Answer 1

select cust_id, count(1)
from
       ( select cust_id
         from table_a
         union all
         select cust_id
         from table_b
group by cust_idExample:
SQL> select deptno, count(1)
  2  from scott.emp
  3  group by deptno;
    DEPTNO   COUNT(1)
        30          6
        20          5
        10          3
SQL> select deptno, count(1)
  2  from
  3     (select deptno
  4      from scott.emp tab_a
  5      union all
  6      select deptno
  7      from scott.emp tab_b
  8     )
  9  group by deptno;
    DEPTNO   COUNT(1)
        30         12
        20         10
        10          6
SQL> Cheers,