Question on an aggregate query

Question

DB Version:10gR2
I have four tables : container1, container2, container3, container4. All these tables have the same structure(have two columns : ITEM_TYPE, QUANTITY). ITEM_TYPE columns in all these tables are interlinked.
create table container1
(item_type VARCHAR2(35),--Container1's PK
quantity  number
create table container2
(item_type VARCHAR2(35),--Container2's PK
quantity  number
create table container3
(item_type VARCHAR2(35),--Container3's PK
quantity  number
create table container4
(item_type VARCHAR2(35),--Container4's PK
quantity  number
insert into container1 values ('APPLE',15)
insert into container2 values ('APPLE',20)
insert into container3 values ('APPLE',30)
insert into container4 values ('APPLE',45)
insert into container1 values ('ORANGE',5)
insert into container2 values ('ORANGE',10)
insert into container3 values ('ORANGE',25)
insert into container4 values ('ORANGE',30)
SELECT * FROM CONTAINER1;
ITEM_TYPE                             QUANTITY
APPLE                                       15
ORANGE                                       5
SELECT * FROM CONTAINER2;
ITEM_TYPE                             QUANTITY
APPLE                                       20
ORANGE                                      10
SELECT * FROM CONTAINER3;
ITEM_TYPE                             QUANTITY
APPLE                                       30
ORANGE                                      25
SELECT * FROM CONTAINER4;
ITEM_TYPE                             QUANTITY
APPLE                                       45
ORANGE                                      30                            I want to generate a report which will return the sum of all the quantity (15+20+30+45) in these 4 table for a particular item_type
The result should look like
  ITEM_TYPE    TOTAL_QUANTITY
  APPLE          110
  ORANGE               70Can i do this like
  SELECT item_type,
--logic required
--logic required
  FROM          container1 INNER JOIN container2
  INNER JOIN     container3 INNER JOIN  container4
  ON          container1.item_type=container2.item_type
  AND          container3.item_type=container4.item_type
  GROUP BY     item_type;or should i use more complex grouping/aggregate functions?
Edited by: user10450365 on Jan 7, 2009 1:20 AM

Answer 1

else you can do this:
SQL> SELECT
  2  container1.item_type,
  3  (container1.quantity + container2.quantity + container3.quantity + container4.quantity) qty
  4  FROM
  5  container1
  6  INNER JOIN CONTAINER2 on  (container1.item_type = container2.item_type)
  7  INNER JOIN CONTAINER3 on  (container1.item_type = container3.item_type)
  8  INNER JOIN CONTAINER4 on  (container1.item_type = container4.item_type)
  9  /
ITEM_TYPE                                  QTY                                 
APPLE                                      110                                 
ORANGE                                      70