我在计算发票PL / SQL的正确总额时遇到麻烦

Question

I am trying to create a function and procedure which calculates the total cost for a specific car service. Listing all the individual cost of parts and the service cost, and producing a total which updates the invoice table.

I am currently experiencing a double charge for the service cost, I am thinking that there is problems with the logic as the total cost for all services are showing. I want to limit the part cost for each specific service.

Here is a demo build of my databases which I have created on SQL+.

SERVICE

CREATE TABLE SERVICE
(SERVICE_ID VARCHAR2 (3) PRIMARY KEY,       
DATE_OF_SERVICE DATE NOT NULL,
TIME VARCHAR2 (8)NOT NULL,              
STAFF_RECORDED VARCHAR2 (3)NOT NULL,            
STAFF_SERVICING VARCHAR2 (3)NOT NULL,           
SERVICE_TYPE_ID VARCHAR2 (1)NOT NULL,           
CAR_ID VARCHAR2 (3)NOT NULL,
BRANCH_ID VARCHAR2 (3)NOT NULL);

INSERT INTO SERVICE VALUES ('01', '14/JAN/2013', '11.15', '01', '06', '1', '01','01');
INSERT INTO SERVICE VALUES ('02','14/JAN/2013', '11.15', '01', '06', '1', '01','01');


PART_SERVICE

CREATE TABLE PART_SERVICE
(PART_ID VARCHAR2 (3),
SERVICE_ID VARCHAR2 (3));

INSERT INTO PART_SERVICE VALUES ('01', '01');
INSERT INTO PART_SERVICE VALUES ('02', '01');

INVOICE

CREATE TABLE INVOICE
(INVOICE_ID VARCHAR2 (3) PRIMARY KEY,               
CUSTOMER_ID VARCHAR2 (3),           
SERVICE_ID VARCHAR2 (3),                            
TOTAL_COST NUMBER (10,2));

INSERT INTO INVOICE VALUES ('01', '01', '01',NULL);

CREATE TABLE SERVICE_TYPE
(SERVICE_TYPE_ID VARCHAR2 (1) PRIMARY KEY,  
SERVICE_NAME VARCHAR2 (15)NOT NULL,
SERVICE_COST NUMBER (5,2)NOT NULL);

INSERT INTO SERVICE_TYPE VALUES ('1', 'FULL SERVICE', 140.00);

PART

CREATE TABLE PART
(PART_ID VARCHAR2(3) PRIMARY KEY,           
PART_NAME VARCHAR2 (20)NOT NULL,
PART_TYPE VARCHAR2 (20)NOT NULL,
PART_PRICE NUMBER (5,2)NOT NULL);

INSERT INTO PART VALUES ('01', 'ABS sensors', 'Electrical', '200.00');
INSERT INTO PART VALUES ('02', 'Light bulbs', 'Electrical', '50.00');

---

SET SERVEROUTPUT ON
SET ECHO ON

CREATE OR REPLACE FUNCTION INVOICE_TOTAL
(i_invoice invoice.invoice_id%TYPE)

RETURN NUMBER
IS
v_invoice_total invoice.total_cost%TYPE;

BEGIN

SELECT SUM(NVL(PART_PRICE+SERVICE_COST,0))
INTO v_invoice_total
FROM SERVICE, PART, SERVICE_TYPE, PART_SERVICE
WHERE SERVICE_TYPE.SERVICE_TYPE_ID = SERVICE.SERVICE_TYPE_ID
AND PART.PART_ID = PART_SERVICE.PART_ID
AND SERVICE.SERVICE_ID = PART_SERVICE.SERVICE_ID
AND SERVICE.SERVICE_ID = i_invoice;

IF v_invoice_total IS NULL THEN
    v_invoice_total := 0;
END IF;

RETURN v_invoice_total;

END;
/

---

CREATE OR REPLACE PROCEDURE TOTALCOST
AS
CURSOR c_invoice
IS
SELECT SERVICE_ID
FROM SERVICE;

v_invoice       invoice.invoice_id%TYPE;
v_invoice_total_cost    invoice.total_cost%TYPE;

BEGIN
OPEN c_invoice;
LOOP
FETCH c_invoice INTO v_invoice;
EXIT WHEN c_invoice%NOTFOUND;

  v_invoice_total_cost := INVOICE_TOTAL(v_invoice);

UPDATE invoice
SET total_cost = v_invoice_total_cost
WHERE invoice_id = v_invoice;

DBMS_OUTPUT.PUT_LINE('PART PRICE:'|| TO_CHAR(v_invoice_total_cost));

END LOOP;

DBMS_OUTPUT.PUT_LINE('Total = '|| TO_CHAR(v_invoice_total_cost));
CLOSE c_invoice;
END;
/

---

exec TOTALCOST;

The actual output is:

PART PRICE:530
PART PRICE:0
PART PRICE:0
PART PRICE:0
PART PRICE:0
Total = 0

What I am trying to get:

SERVICE = '01'
PART PRICE = 200
PART PRICE = 50
SERVICE PRICE = 140

Total Price: 390

Answer 1

I think the problem is in your seed data. You have this:

CREATE TABLE PART_SERVICE
(PART_ID VARCHAR2 (3),
SERVICE_ID VARCHAR2 (3));

INSERT INTO PART_SERVICE VALUES ('01', '01');
INSERT INTO PART_SERVICE VALUES ('02', '01');

But I think the second insert is transposing the values, and you meant to do this:

INSERT INTO PART_SERVICE VALUES ('01', '01');
INSERT INTO PART_SERVICE VALUES ('01', '02'); -- swapped values.

Answer 2

Please change the JOINs in your function to as shown below, it makes it more readable.

Because your query will have two PARTS the SERVICE_TYPE table row will be added twice if you write it that way (explaining the additional 140).
Your function must be something like

SELECT x.PartCost + st.SERVICE_COST
INTO v_invoice_total
FROM SERVICE_TYPE st
JOIN (
    SELECT SUM(PART_PRICE) [PartCost], s.SERVICE_ID, s.SERVICE_TYPE_ID
    FROM SERVICE s
        JOIN PART_SERVICE ps ON s.SERVICE_ID = ps.SERVICE_ID
        JOIN PART p ON ps.PART_ID = p.PART_ID
    GROUP BY s.SERVICE_ID, s.SERVICE_TYPE_ID
    ) as x ON x.SERVICE_TYPE_ID = st.SERVICE_TYPE_ID

Answer 3

跌倒/ sql要求您大跌幅，如果小跌幅将无法做到