PL SQL Procedure Exercise - stored-procedures

Question

I'm not really sure how to approach this question.. I understand the basic syntax of writing a procedure. This is an exercise for a beginner database class (which seems to be at a level way above beginner)
Create a procedure to place a purchase order for a specified date based on data in the inventory report table.
Name the procedure placeorder [procedure name is important].
The procedure should take one parameter: inputDate (use the datatype of the PODate column in PURCHASEORDERS). The input date format accepted should be: 'DD-MON-YYYY', e.g., 01-JAN-2017.
For each raw material in the Inventory Report table (where: ReportDate matches inputDate), make a separate entry in the PURCHASEORDERS table for a next-day delivery order and a same-day delivery order (each raw material may generate up to 2 inserts).
Corresponding order type should be either next_day or same_day
Only make an entry (insertion) in PURCHASEORDERS if needed, i.e., if
an entry exists for a raw material and report date combination in the
Inventory Report table. If the Inventory Report for a day (e.g.,
30-NOV-2017) has a 0 value for the ordersameday attribute, it means
no same_day order is needed.
If no order is needed for the provided input date (i.e., no order at all across ALL raw materials), raise an application error with a message: “no order needed” (see Triggers and Procedures tutorial on D2L for an example of how to raise this error). You can use any suitable error-number.  Your procedure should leave the “Price” (for the purchase order) empty (i.e., it can remain null). Assume it’ll be populated later.
Thanks!

Answer 1

Sorry this is what i've written so far.. #kara
CREATE OR REPLACE PROCEDURE placeorder (inputDate in DATE)
AS
new_inputDate PURCHASEORDERS.PODate%TYPE;
new_orderType PURCHASEORDERS.ORDERTYPE%TYPE;
c_orderSameDay INVENTORYREPORT.ORDERSAMEDAY%TYPE;
c_orderNextDay INVENTORYREPORT.ORDERNEXTDAY%TYPE;
CURSOR C1 IS
SELECT REPORTDATE INTO inputDate FROM dual;
SELECT ir.itemId, ir.ORDERSAMEDAY, ir.ORDERNEXTDAY FROM INVENTORYREPORT
WHERE
ir.REPORTDATE = inputDate;
BEGIN
OPEN C1;
WHILE C1%FOUND LOOP
FETCH C1 INTO new_inputDate, new_orderType, c_orderSameDay, c_orderNextDay;
IF c_orderSameDay > 0
THEN INSERT INTO PURCHASEORDERS (new_orderType) VALUES (orderSameDay);
ELSE <application error>;
END IF;
IF c_orderNextDay > 0
THEN INSERT INTO PURCHASEORDERS (new_orderType) VALUES (orderNextDay);
ELSE <application error>;
END IF;
END LOOP;
CLOSE C1;
END;
/

Answer 2

#kara I added to the if statements but still getting a couple errors when trying to compile the procedure. It this doing what it's supposed to be doing?
CREATE OR REPLACE PROCEDURE placeorder (inputDate in DATE)
AS
new_inputDate PURCHASEORDERS.PODate%TYPE;
new_orderType PURCHASEORDERS.ORDERTYPE%TYPE;
c_orderSameDay INVENTORYREPORT.ORDERSAMEDAY%TYPE;
c_orderNextDay INVENTORYREPORT.ORDERNEXTDAY%TYPE;
CURSOR C1 IS
SELECT REPORTDATE INTO inputDate FROM dual;
SELECT ir.itemId, ir.ORDERSAMEDAY, ir.ORDERNEXTDAY FROM INVENTORYREPORT
WHERE
ir.REPORTDATE = inputDate;
BEGIN
OPEN C1;
WHILE C1%FOUND LOOP
FETCH C1 INTO new_inputDate, new_orderType, c_orderSameDay, c_orderNextDay;
IF c_orderSameDay > 0
THEN INSERT INTO PURCHASEORDERS (new_orderType) VALUES (orderSameDay);
ELSE INSERT INTO PURCHASEORDERS (new_orderType) VALUES ('no order needed');
END IF;
IF c_orderNextDay > 0
THEN INSERT INTO PURCHASEORDERS (new_orderType) VALUES (orderNextDay);
ELSE INSERT INTO PURCHASEORDERS (new_orderType) VALUES ('no order needed');
END IF;
FETCH C1 INTO new_inputDate, new_orderType, c_orderSameDay, c_orderNextDay;
END LOOP;
CLOSE C1;
COMMIT;
END placeorder;
/

Answer 3

There are a bunch of examples how to create a procedure. Here a small one:
CREATE OR REPLACE PROCEDURE ProcName (paraName IN VARCHAR2)
AS
myStringVariable VARCHAR2 (4000);
myDateVariable DATE;
BEGIN
SELECT orderDateAsString
INTO myStringVariable
FROM orders
WHERE orderId = paraName;
myDateVariable := TO_DATE (myStringVariable, 'dd.mm.yyyy HH24:MI:SS'); -- '13.03.2018 23:59:59'
dbms_output.put_line('My date: ' || myStringVariable);
END;
And some example-code, to call the procedure:
begin
ProcName('1234');
end;
But you should look at your exercise first and think about you tasks. I think, this is what you got to do:
Create a Table.
Create Insert-Statements for the table
Create some PL/SQL-code which performs the insert with conditions.
move the PL/SQL-code to a procedure.
Call the procedure with a PL/SQL-block.
Explaination for you edits
You should build your code step-by-step if. You got multiple errors.
Check you Cursor. The Select-statement is not valid.
You wrote two selects.
You do not use new_inputdate. Why did you define it and what should it do?
Run you SELECT-statement alone without your code. if you like your data you can put it in an cursor.
Example with your code:
CREATE OR REPLACE PROCEDURE placeorder (inputDate IN DATE)
AS
-- new_inputDate PURCHASEORDERS.PODate%TYPE; --you don't use this one
new_orderType PURCHASEORDERS.ORDERTYPE%TYPE;
c_orderSameDay INVENTORYREPORT.ORDERSAMEDAY%TYPE;
c_orderNextDay INVENTORYREPORT.ORDERNEXTDAY%TYPE;
-- you mixed up your cursors. seems like you didn't try the select-statement alone..
CURSOR C2
IS
SELECT ir.itemId, ir.ORDERSAMEDAY, ir.ORDERNEXTDAY
FROM INVENTORYREPORT
WHERE ir.REPORTDATE = inputDate;
BEGIN
OPEN C2;
WHILE C2%FOUND
LOOP
FETCH C2 INTO new_orderType, c_orderSameDay, c_orderNextDay;
NULL; -- Do something
END LOOP;
CLOSE C2;
END;
/
Think about what you want to do in the loop. Build a small skript with the variables and think about what it should do:
Example-Skript of you Loop-content:
DECLARE
-- new_inputDate PURCHASEORDERS.PODate%TYPE; --you don't use this one
new_orderType NUMBER := 0;
c_orderSameDay NUMBER := 1;
c_orderNextDay NUMBER := 2;
BEGIN
-- this is what you're doing in you loop.
IF c_orderSameDay > 0 -- check if c_orderSameDay is greater than 0? In Oracle you use 'NULL' as empty value. Perhaps it should be 'c_orderSameDay IS NOT NULL'
THEN
INSERT INTO PURCHASEORDERS (new_orderType) -- you perform your insert.
VALUES (orderSameDay);
ELSE
RAISE; -- you raise an exception? this means c_orderSameDay has alsway to be set.
END IF;
IF c_orderNextDay > 0
THEN
INSERT INTO PURCHASEORDERS (new_orderType)
VALUES (orderNextDay);
ELSE
RAISE; -- you raise an exception? this means c_orderNextDay has alsway to be set.
END IF;
END;