Generating multiple rows from one physical row

Question

I was wondering if anyone has done or knows how to generate multiple rows for one physical row. In my query "SELECT Cust_No, Amount from Balances" if the amount is > 99,999.99 I want 2 rows returned, one with an amount of 90,000.00 and the other with an amount of 9,999.99. I'm thinking I need to use a view or function to return a result set but I'm not sure how.
Thanks in advance,
Allen Davis
[email protected]

Answer 1

James,
Well your right in that you need a function, but also 3 views to accomplish that. I just wrote up the sql below and tested it. Basically you want the first view to return all records less than your cap of 99,999, thoes that exceed that will always return as 90,000 (see example on record PK 774177177). The second view returns money that remains AFTER the cap (in your case 9,999). The second view though also has to excude the ones less than the CAP.
DATA and TABLE layout
1) Table is called T1, columns are PK : primary key value, and N2 : some number column holding the MONEY amount
2) data is below fromtable called t1 (10 records) ...
select pk,n2 from t1 order by pk
PK     N2
117165529     100
274000876     200000
350682010     9999
737652242     90000
774177177     99999
1369893126     1000
1663704428     100000
1720465556     8888
1793125955     0
1972069382     1000000
Now see the records with money at 99,999 (just like in your example). You want 2 records, so the VIEWS now come into play. The view itself CALLS the function, this occurs when you select from the view. The function will either return 90,000 (your defined cap) or the remained after subtracting the money from 90,000. The 3 views are defined below (the FUNCTION which is shown after will have to be compiled first) ...
--[VIEWS START]
CREATE OR REPLACE VIEW VIEW1
(PK,SHOW_MONEY)
AS SELECT PK,FN_TRIM_MONEY(N2,1) FROM T1;
CREATE OR REPLACE VIEW VIEW2
(PK,SHOW_MONEY)
AS SELECT PK,FN_TRIM_MONEY(N2,2) FROM T1 WHERE N2 >= 99999;
CREATE OR REPLACE VIEW VIEW_ALL
(PK,SHOW_MONEY)
AS
SELECT * FROM VIEW1
UNION ALL
SELECT * FROM VIEW2;
--[VIEWS END]
OK now for the actual function ...
--[FUNCTION START]
CREATE OR REPLACE FUNCTION
FN_TRIM_MONEY
PI_MONEY NUMBER,
PI_VIEW_ID NUMBER
RETURN NUMBER AS
LS_TEMP VARCHAR2(2000);
LI_TEMP NUMBER;
LD_TEMP DATE;
LI_CON_MONEY_MAX CONSTANT NUMBER := 90000;
LS_RETURN VARCHAR2(2000);
BEGIN
IF (PI_MONEY > LI_CON_MONEY_MAX) THEN
IF PI_VIEW_ID = 1 THEN
LI_TEMP := LI_CON_MONEY_MAX;
ELSIF PI_VIEW_ID = 2 THEN
LI_TEMP := (PI_MONEY - LI_CON_MONEY_MAX);
END IF;
ELSE
LI_TEMP := PI_MONEY;
END IF;
IF LI_TEMP < 0 THEN
LI_TEMP := 0;
END IF;
LS_RETURN := LI_TEMP;
RETURN LS_RETURN;
END;
SHOW ERRORS;
--[FUNCTION END]
I compiled the function and views with no errors. This is what I get when I query the 3 views ...
--[VIEW 1]
PK     SHOW_MONEY
117165529     100
274000876     90000
350682010     9999
737652242     90000
774177177     90000
1369893126     1000
1663704428     90000
1720465556     8888
1793125955     0
1972069382     90000
--[VIEW 2]
PK     SHOW_MONEY
274000876     110000
774177177     9999
1663704428     10000
1972069382     910000
--[VIEW ALL]
PK     SHOW_MONEY
117165529     100
274000876     90000
274000876     110000
350682010     9999
737652242     90000
774177177     90000
774177177     9999
1369893126     1000
1663704428     90000
1663704428     10000
1720465556     8888
1793125955     0
1972069382     90000
1972069382     910000
So notice the PK entry 774177177 listed twice, once with 90,000 and other with 9,999. Also notice we now have 14 records from the original 10, meaning 4 records qualified for the split (all data from VIEW 2).
This is why Oracle kicks ass, views and functions are very powerful when used together and can return pretty much anything.
Thanks,
Tyler D.
[email protected]