create views and triggers in oracle sql - sql

Question

I need help with creating a view and then triggers for the following: update salesperson commission(10% of sale), inventory quantity, and customer balance when each invoice line item is entered.
This is what I have right now for the view:
CREATE OR REPLACE VIEW NEW_INVOICE_LINE_ITEM
AS
SELECT COMMISSION, INV_QUANTITY, CUSTOMER_BALANCE
FROM SALESPERSON, INVENTORY, CUSTOMER;
This is what I have for the trigger:
CREATE OR REPLACE TRIGGER UPDATE_COMMISSION
AFTER INSERT ON INVOICE_LINE_ITEM FOR EACH ROW
BEGIN
UPDATE SALESPERSON
SET COMMISSION = (SALE_PRICE * QUANTITY_SOLD) *.10
WHERE :NEW.COMMISSION = SALESPERSON.COMMISSION;
END;
I keep on getting the error: bad bind variable 'new.commission'
This my database schema below:
DROP TABLE PO_LINE_ITEM;
DROP TABLE PURCHASE_ORDER;
DROP TABLE VENDOR;
DROP TABLE INVOICE_LINE_ITEM;
DROP TABLE INVENTORY;
DROP TABLE INVOICE;
DROP TABLE SALESPERSON;
DROP TABLE CUSTOMER;
CREATE TABLE CUSTOMER
(CUSTOMER_ID DECIMAL(2,0) PRIMARY KEY,
CUSTOMER_NAME CHAR(25),
CUSTOMER_ADDRESS CHAR(15),
CUSTOMER_ZIPCODE DECIMAL(5,0),
CUSTOMER_CITY CHAR(15),
CUSTOMER_STATE CHAR(2),
CUSTOMER_BALANCE DECIMAL(4,2)
);
CREATE TABLE SALESPERSON
(SALESPERSON_ID DECIMAL(3,0) PRIMARY KEY,
SALESPERSON_NAME CHAR(25),
COMMISSION DECIMAL(5,2)
);
CREATE TABLE INVOICE
(INVOICE_ID DECIMAL(3,0),
CUSTOMER_ID DECIMAL(2,0),
SALESPERSON_ID DECIMAL(3,0),
ITEM_NUM DECIMAL(4,0),
INVOICE_DATE DATE,
PRIMARY KEY (CUSTOMER_ID, SALESPERSON_ID),
FOREIGN KEY (CUSTOMER_ID) REFERENCES CUSTOMER,
FOREIGN KEY (SALESPERSON_ID) REFERENCES SALESPERSON
);
CREATE TABLE INVENTORY
(INV_NUM DECIMAL(4,0) PRIMARY KEY,
DESCRIPTION CHAR(10),
INV_QUANTITY DECIMAL(4,0),
INV_PRICE DECIMAL(7,2),
INV_COST DECIMAL(7,2),
INVOICE_ID DECIMAL(3,0),
ITEM_NUM DECIMAL(4,0),
FOREIGN KEY (INVOICE_ID, ITEM_NUM) REFERENCES INVOICE
);
CREATE TABLE INVOICE_LINE_ITEM
(QUANTITY_SOLD DECIMAL(4,0),
SALE_PRICE DECIMAL(7,2),
INVOICE_ID DECIMAL(3,0),
INV_NUM DECIMAL(4,0),
ITEM_NUM DECIMAL(4,0),
PRIMARY KEY (INVOICE_ID, INV_NUM, ITEM_NUM),
FOREIGN KEY (INVOICE_ID, ITEM_NUM) REFERENCES INVOICE,
FOREIGN KEY (INV_NUM) REFERENCES INVENTORY
);
CREATE TABLE VENDOR
(VENDOR_ID DECIMAL(2,0) PRIMARY KEY,
VENDOR_NAME CHAR(25),
CITY CHAR(15),
STATE CHAR(2),
VENDOR_BALANCE DECIMAL(4,2)
);
CREATE TABLE PURCHASE_ORDER
(PURCHASE_ORDER_ID DECIMAL(2,0) PRIMARY KEY,
BALANCE DECIMAL(4,2),
SHIPMENT CHAR(10),
PURCHASE_ORDER_DATE DATE,
VENDER_ID DECIMAL (2,0),
FOREIGN KEY (VENDER_ID) REFERENCES VENDOR
);
CREATE TABLE PO_LINE_ITEM
(PO_DATE DATE,
PO_BALANCE DECIMAL(4,0),
ITEM_NUM DECIMAL(4,0),
INV_QUANTITY DECIMAL(4,0),
INV_NUM DECIMAL(4,0),
PURCHASE_ORDER_ID DECIMAL(2,0),
PRIMARY KEY (INV_NUM, PURCHASE_ORDER_ID),
FOREIGN KEY (INV_NUM) REFERENCES INVENTORY,
FOREIGN KEY (PURCHASE_ORDER_ID) REFERENCES PURCHASE_ORDER);
Thanks in advance!

Answer 1

Table invoice_line_item does not contain column commission, this is the reason for bad bind variable error. You should rewrite your trigger code like here:
create or replace trigger update_commission
after insert on invoice_line_item for each row
begin
update salesperson sp
set sp.commission = sp.commission + (:new.sale_price * :new.quantity_sold * .1)
where sp.salesperson_id =
(select salesperson_id
from invoice i
where i.invoice_id = :new.invoice_id);
end;
In your view you did not attach conditions how to join tables, here is the example how to do this:
create or replace view vw_invoices as
select ili.invoice_id, ili.quantity_sold, ili.sale_price,
i.salesperson_id, sp.salesperson_name
from invoice_line_item ili
join invoice i on i.invoice_id = ili.invoice_id
join salesperson sp on sp.salesperson_id = i.salesperson_id;
Depending on which informations you want to show - connect proper tables and use correct joins.