Multiplying Columns using a WITH clause - mysql

Question

Hello all Im trying to Find the total value of an order Through Arthmetic(Quanity * Unit_price) which i can do BUT the question wants me to do so using a nest query and a WITH clause. How would I implement the WITH clause?
below is what ive done but not meeting the procedure requirements
SELECT ORDER_ID
FROM ORDERS
WHERE ORDER_ID IN
(SELECT(QUANTITY * UNIT_PRICE) AS TOTAL_VALUE
FROM ORDER_DETAIL)
ODER BY ORDER_ID ASC;
CREATE TABLE ORDERS
(
ORDER_ID DECIMAL(9) NOT NULL,
CUSTOMER_CODE VARCHAR(5) NOT NULL,
EMPLOYEE_ID DECIMAL(9) NOT NULL,
ORDER_DATE DATE NOT NULL,
REQUIRED_DATE DATE,
SHIPPED_DATE DATE,
SHIP_VIA VARCHAR(40),
FREIGHT DECIMAL(10,2) DEFAULT 0,
SHIP_NAME VARCHAR(40),
SHIP_ADDRESS VARCHAR(60),
SHIP_CITY VARCHAR(15),
SHIP_REGION VARCHAR(15),
SHIP_POSTAL_CODE VARCHAR(10),
SHIP_COUNTRY VARCHAR(15),
CONSTRAINT PK_ORDERS PRIMARY KEY (ORDER_ID),
CONSTRAINT FK_CUSTOMER_CODE FOREIGN KEY (CUSTOMER_CODE) REFERENCES CUSTOMER(CUSTOMER_CODE),
CONSTRAINT FK_EMPLOYEE_ID FOREIGN KEY (EMPLOYEE_ID) REFERENCES EMPLOYEE(EMPLOYEE_ID),
CONSTRAINT FK_SHIP_VIA FOREIGN KEY (SHIP_VIA) REFERENCES SHIPPER(COMPANY_NAME)
);
CREATE TABLE ORDER_DETAIL
(
ORDER_ID DECIMAL(9) NOT NULL,
PRODUCT_NAME VARCHAR(40) NOT NULL,
UNIT_PRICE DECIMAL(10,2) NOT NULL DEFAULT 0,
QUANTITY DECIMAL(9) NOT NULL DEFAULT 1 ,
DISCOUNT DECIMAL(4,2) NOT NULL DEFAULT 0,
CONSTRAINT PK_ORDER_DETAIL PRIMARY KEY (ORDER_ID, PRODUCT_NAME),
CONSTRAINT FK_ORDER_ID FOREIGN KEY (ORDER_ID) REFERENCES ORDERS (ORDER_ID),
CONSTRAINT FK_PRODUCT_NAME FOREIGN KEY (PRODUCT_NAME) REFERENCES PRODUCT (PRODUCT_NAME),
CONSTRAINT CK_ORDER_DETAIL_UNIT_PRICE CHECK (UNIT_PRICE >= 0),
CONSTRAINT CK_ORDER_DETAIL_QUANTITY CHECK (QUANTITY > 0),
CONSTRAINT CK_ORDER_DETAIL_DISCOUNT CHECK (DISCOUNT between 0 and 1)
);
i think i might need to use this table but i am unsure(TABLE PRODUCT)
CREATE TABLE PRODUCT
(
PRODUCT_NAME VARCHAR(40) NOT NULL,
SUPPLIER_NAME VARCHAR(40) NOT NULL,
CATEGORY_NAME VARCHAR(30) NOT NULL,
QUANTITY_PER_UNIT VARCHAR(20),
UNIT_PRICE DECIMAL(10,2) NOT NULL DEFAULT 0,
UNITS_IN_STOCK DECIMAL(9) NOT NULL DEFAULT 0,
UNITS_ON_ORDER DECIMAL(9) NOT NULL DEFAULT 0,
REORDER_LEVEL DECIMAL(9) NOT NULL DEFAULT 0,
DISCONTINUED CHAR(1) NOT NULL DEFAULT 'N',
CONSTRAINT PK_PRODUCT PRIMARY KEY (PRODUCT_NAME),
CONSTRAINT FK_CATEGORY_NAME FOREIGN KEY (CATEGORY_NAME) REFERENCES CATEGORY(CATEGORY_NAME),
CONSTRAINT FK_SUPPLIER_NAME FOREIGN KEY (SUPPLIER_NAME) REFERENCES SUPPLIER(COMPANY_NAME),
CONSTRAINT CK_PRODUCT_UNIT_PRICE CHECK (UNIT_PRICE >= 0),
CONSTRAINT CK_PRODUCT_UNITS_IN_STOCK CHECK (UNITS_IN_STOCK >= 0),
CONSTRAINT CK_PRODUCT_UNITS_ON_ORDER CHECK (UNITS_ON_ORDER >= 0),
CONSTRAINT CK_PRODUCT_REORDER_LEVEL CHECK (REORDER_LEVEL >= 0),
CONSTRAINT CK_PRODUCT_DISCONTINUED CHECK (DISCONTINUED in ('Y','N'))
);
This is the exact question
Insert into a file solution1.sql implementation of the following query as
SELECT statement with WITH clause.
Find all orders such that a value of each order is greater than an average value of all orders submitted so far. List in each line of output an order identifier, a total value of an order, and an average value of all orders. The results must be sorted in the descending order of a total value of each order.
"A total value of an order must be computed as the summation of unit price * quantityover all items included in the order. The query must be implemented as a sequence of subquery definitions following WITH keyword and ended with the final SELECT.
(i) The first subquery definition must find a total value of each order together with an order identifier (attribute order_id). "
im currently on (i)

Answer 1

Ignoring for a moment the subsequent requirements, the first block of code might look like this:
SELECT o.some
, o.columns
, o.from_orders
, x.total_value
FROM orders o
JOIN
( SELECT order_id
, SUM(quantity * unit_price) total_value
FROM order_detail
GROUP
BY order_id
) x
ON x.order_id = o.order_id