I'm using oracle to output line items in from a shopping app. Each item has a quantity field that may be greater than 1 and if it is, I'd like to return that row N times.
Here's what I'm talking about for a table
product_id, quanity
1, 3,
2, 5
And I'm looking a query that would return
1,3
1,3
1,3
2,5
2,5
2,5
2,5
2,5
Is this possible? I saw this answer for SQL Server 2005 and I'm looking for almost the exact thing in oracle. Building a dedicated numbers table is unfortunately not an option.
I've used 15 as a maximum for the example, but you should set it to 9999 or whatever the maximum quantity you will support.
create table t (product_id number, quantity number);
insert into t values (1,3);
insert into t values (2,5);
select t.*
from t
join (select rownum rn from dual connect by level < 15) a
on a.rn <= t.quantity
order by 1;
First create sample data:
create table my_table (product_id number , quantity number);
insert into my_table(product_id, quantity) values(1,3);
insert into my_table(product_id, quantity) values(2,5);
And now run this SQL:
SELECT product_id, quantity
FROM my_table tproducts
,( SELECT LEVEL AS lvl
FROM dual
CONNECT BY LEVEL <= (SELECT MAX(quantity) FROM my_table)) tbl_sub
WHERE tbl_sub.lvl BETWEEN 1 AND tproducts.quantity
ORDER BY product_id, lvl;
PRODUCT_ID QUANTITY
---------- ----------
1 3
1 3
1 3
2 5
2 5
2 5
2 5
2 5
This question is propably same as this: how to calc ranges in oracle
Update solution, for Oracle 9i:
You can use pipelined_function() like this:
CREATE TYPE SampleType AS OBJECT
(
product_id number,
quantity varchar2(2000)
)
/
CREATE TYPE SampleTypeSet AS TABLE OF SampleType
/
CREATE OR REPLACE FUNCTION GET_DATA RETURN SampleTypeSet
PIPELINED
IS
l_one_row SampleType := SampleType(NULL, NULL);
BEGIN
FOR cur_data IN (SELECT product_id, quantity FROM my_table ORDER BY product_id) LOOP
FOR i IN 1..cur_data.quantity LOOP
l_one_row.product_id := cur_data.product_id;
l_one_row.quantity := cur_data.quantity;
PIPE ROW(l_one_row);
END LOOP;
END LOOP;
RETURN;
END GET_DATA;
/
Now you can do this:
SELECT * FROM TABLE(GET_DATA());
Or this:
CREATE OR REPLACE VIEW VIEW_ALL_DATA AS SELECT * FROM TABLE(GET_DATA());
SELECT * FROM VIEW_ALL_DATA;
Both with same results.
(Based on my article pipelined function)