SQL ORACLE Problems with three queries - sql

Question

I have three tables orders, orderdetails and customers.
The orders table has these columns:
ORDERID, CUSTOMERID, EMPLOYEEID, TERRITORYID,
ORDERDATE, REQUIREDDATE, SHIPPEDDATE,
SHIPVIA, FREIGHT, SHIPNAME,
SHIPADDRESS, SHIPCITY, SHIPREGION,
SHIPPOSTALCODE, SHIPCOUNTRY
The orderdetails table has these columns:
ORDERID, PRODUCTID, UNITPRICE, QUANTITY, DISCOUNT
And the customers table has these columns:
CUSTOMERID, COMPANYNAME, CONTACTNAME,
CONTACTTITLE, ADDRESS, CITY, REGION,
POSTALCODE, COUNTRY, PHONE, FAX
I have to do three queries:
1 List of orders with a higher total amount (unitprice * quantity * (1 - discount)) provided that the total amount is greater than 10000
I did it like this:
SELECT orderid
FROM orders
JOIN orderdetails USING (orderid)
GROUP BY orderid
HAVING SUM (unitprice * quantity * (1 - discount)) > 10000;
2 Order with the highest total amount (including discount)
I did it like this:
SELECT MAX (orderid),
SUM (unitprice * quantity * (1 - discount)) as price
FROM orders
JOIN orderdetails USING (orderid)
ORDER BY price DESC;
3 show the customerid and the freight (transport) of the customers who have spent more than 2000 freight on all their orders
I have not been able to do this
SELECT customerid,freight
FROM customers
JOIN orders USING (customerid)
HAVING Count (freight) > 2000;
I want to know if I did #1 and #2 correctly or is there a better way to do it and how can I solve #3.
Thank you very much to all.

Answer 1

You don't need the customers table (since the orders table contains both freight and customerid) and need to have a GROUP BY clause and aggregate the freight column in the SELECT clause (and probably want to use SUM rather than COUNT but you haven't provided any sample data so it is difficult to tell):
SELECT customerid,
SUM(freight)
FROM orders
GROUP BY
customerid
HAVING SUM(freight) > 2000;

Answer 2

With Sample data like here:
WITH
orders (ORDERID, CUSTOMERID, EMPLOYEEID, TERRITORYID, ORDERDATE, REQUIREDDATE, SHIPPEDDATE, SHIPVIA, FREIGHT, SHIPNAME,
SHIPADDRESS, SHIPCITY, SHIPREGION, SHIPPOSTALCODE, SHIPCOUNTRY) AS
(
Select 101, 1, 11, 'T1', DATE '2023-01-03', DATE '2023-01-24', DATE '2023-01-04', 'via A', 1500, 'A SHIP', 'Address 1', 'A CITY', 'A REGION', 'A ZIP', 'A COUNTRY' From Dual Union All
Select 102, 1, 11, 'T1', DATE '2023-01-03', DATE '2023-01-24', DATE '2023-01-04', 'via A', 250, 'A SHIP', 'Address 1', 'A CITY', 'A REGION', 'A ZIP', 'A COUNTRY' From Dual Union All
Select 103, 1, 11, 'T1', DATE '2023-01-03', DATE '2023-01-24', DATE '2023-01-04', 'via A', 500, 'A SHIP', 'Address 1', 'A CITY', 'A REGION', 'A ZIP', 'A COUNTRY' From Dual Union All
Select 104, 2, 11, 'T1', DATE '2023-01-03', DATE '2023-01-24', DATE '2023-01-04', 'via A', 750, 'A SHIP', 'Address 1', 'A CITY', 'A REGION', 'A ZIP', 'A COUNTRY' From Dual Union All
Select 105, 2, 11, 'T1', DATE '2023-01-03', DATE '2023-01-24', DATE '2023-01-04', 'via A', 950, 'A SHIP', 'Address 1', 'A CITY', 'A REGION', 'A ZIP', 'A COUNTRY' From Dual Union All
Select 106, 2, 11, 'T1', DATE '2023-01-03', DATE '2023-01-24', DATE '2023-01-04', 'via A', 1250, 'A SHIP', 'Address 1', 'A CITY', 'A REGION', 'A ZIP', 'A COUNTRY' From Dual Union All
Select 107, 3, 11, 'T1', DATE '2023-01-03', DATE '2023-01-24', DATE '2023-01-04', 'via A', 2500, 'A SHIP', 'Address 1', 'A CITY', 'A REGION', 'A ZIP', 'A COUNTRY' From Dual Union All
Select 108, 4, 11, 'T1', DATE '2023-01-03', DATE '2023-01-24', DATE '2023-01-04', 'via A', 850, 'A SHIP', 'Address 1', 'A CITY', 'A REGION', 'A ZIP', 'A COUNTRY' From Dual Union All
Select 109, 4, 11, 'T1', DATE '2023-01-03', DATE '2023-01-24', DATE '2023-01-04', 'via A', 950, 'A SHIP', 'Address 1', 'A CITY', 'A REGION', 'A ZIP', 'A COUNTRY' From Dual Union All
Select 110, 5, 11, 'T1', DATE '2023-01-03', DATE '2023-01-24', DATE '2023-01-04', 'via A', 1150, 'A SHIP', 'Address 1', 'A CITY', 'A REGION', 'A ZIP', 'A COUNTRY' From Dual
),
details (ORDERID, PRODUCTID, UNITPRICE, QUANTITY, DISCOUNT) AS
(
Select 101, 1001, 700, 5, 0.1 From Dual Union All
Select 101, 1002, 700, 5, 0.1 From Dual Union All
Select 102, 1003, 800, 2, 0.1 From Dual Union All
Select 102, 1004, 700, 2, 0.1 From Dual Union All
Select 103, 1003, 900, 5, 0.3 From Dual Union All
Select 103, 1004, 700, 6, 0.1 From Dual Union All
Select 103, 1005, 700, 7, 0.1 From Dual Union All
Select 104, 1001, 700, 1, 0.1 From Dual Union All
Select 104, 1002, 900, 1, 0.2 From Dual Union All
Select 105, 1002, 900, 3, 0.1 From Dual Union All
Select 106, 1005, 700, 1, 0.1 From Dual Union All
Select 107, 1003, 700, 7, 0.1 From Dual Union All
Select 108, 1004, 700, 8, 0.2 From Dual Union All
Select 109, 1003, 900, 8, 0.1 From Dual Union All
Select 109, 1004, 900, 9, 0.3 From Dual Union All
Select 110, 1005, 700, 9, 0.1 From Dual
),
customers(CUSTOMERID, COMPANYNAME, CONTACTNAME, CONTACTTITLE, ADDRESS, CITY, REGION, POSTALCODE, COUNTRY, FAX) AS
(
Select 1, 'A COMPANY', 'A CONTACT', 'A TITLE', 'Address 1', 'A CITY', 'A REGION', 'A ZIP', 'A COUNTRY', 'A FAX' From Dual Union All
Select 2, 'A COMPANY', 'A CONTACT', 'A TITLE', 'Address 1', 'A CITY', 'A REGION', 'A ZIP', 'A COUNTRY', 'A FAX' From Dual Union All
Select 3, 'A COMPANY', 'A CONTACT', 'A TITLE', 'Address 1', 'A CITY', 'A REGION', 'A ZIP', 'A COUNTRY', 'A FAX' From Dual Union All
Select 4, 'A COMPANY', 'A CONTACT', 'A TITLE', 'Address 1', 'A CITY', 'A REGION', 'A ZIP', 'A COUNTRY', 'A FAX' From Dual Union All
Select 5, 'A COMPANY', 'A CONTACT', 'A TITLE', 'Address 1', 'A CITY', 'A REGION', 'A ZIP', 'A COUNTRY', 'A FAX' From Dual Union All
Select 6, 'A COMPANY', 'A CONTACT', 'A TITLE', 'Address 1', 'A CITY', 'A REGION', 'A ZIP', 'A COUNTRY', 'A FAX' From Dual
)
your 3 answers would be like below:
-- 1.
SELECT ORDERID, Sum(UNITPRICE * QUANTITY * (1 - DISCOUNT)) "TOTAL_10K_PLUS"
FROM orders
JOIN details USING (ORDERID)
GROUP BY ORDERID
HAVING SUM (UNITPRICE * QUANTITY * (1 - DISCOUNT)) > 10000;
/*
ORDERID TOTAL_10K_PLUS
---------- --------------
109 12150
103 11340
*/
-- 2. Changed
SELECT ORDERID, TOTAL "HIGHEST_TOTAL"
FROM
( SELECT o.ORDERID,
MAX(SUM(UNITPRICE * QUANTITY * (1 - DISCOUNT))) OVER(Partition By o.ORDERID) as TOTAL
FROM orders o JOIN details d ON (d.ORDERID = o.ORDERID)
GROUP BY o.ORDERID
ORDER BY TOTAL DESC
)
WHERE ROWNUM = 1
/*
ORDERID HIGHEST_TOTAL
---------- -------------
109 12150
*/
-- 3. Changed
SELECT CUSTOMERID, Sum(FREIGHT) "TOTAL_FREIGHT"
FROM orders
GROUP BY CUSTOMERID
HAVING Sum(FREIGHT) > 2000;
/*
CUSTOMERID TOTAL_FREIGHT
---------- -------------
1 2250
2 2950
3 2500
*/