Problem:
Find the net balance of the total order amount and total payments for each customer.
There are 4 tables involved: OrderDetails, Orders, Payments and Customer.
The total amount order = quantity order * price each [in OrderDetails]
The total payment = sum of different payments for the same order.
Customers are linked to Payments and Orders with CustomerNumber. Orders are linked to OrderDetails with OrderNumber.
I tried joining the 4 tables with the INNER JOIN function.
SELECT
c.customername,
SUM(od.quantityordered * od.priceeach) - SUM(p.amount) AS Net_Balance
FROM
(
(
orderdetails od
INNER JOIN orders o ON od.ordernumber = o.ordernumber
)
INNER JOIN customers c ON o.customernumber = c.customernumber
)
INNER JOIN payments p ON c.customernumber = p.customernumber
GROUP BY c.customername;
The expected results should be 0 for almost every customers.
However, what I have got is the total amount order and total payment are multiplied by some constants. Specifically, the total payment shown is multiplied by the number of payments for each order.
Anybody have any ideas to save my life?
This is a typical issue when dealing with N-M relationships. To solve it, one solution is to move the aggregation to subqueries:
SELECT c.customername, o.amt - p.amt AS Net_Balance
FROM customers c
INNER JOIN (
SELECT ord.customernumber, SUM(det.quantityordered * det.priceeach) as amt
FROM orders ord
INNER JOIN orderdetails det ON ord.ordernumber = det.ordernumber
GROUP BY ord.customernumber
) o ON o.customernumber = c.customernumber
INNER JOIN (
SELECT customernumber, SUM(amount) as amt
FROM payments
GROUP BY customernumber
) p ON p.customernumber = c.customernumber
SELECT c.customername, SUM(od.quantityordered*od.priceeach) as ordersum , SUM(p.amount) as paymentsum'
What's the result of the two columns ?
Is it what you want?
Related
I wasted all the day on one query without success , SOS I need a help :) with a given #CustomerId , I need to query all the Products that linked to customer seller can sell but not sold to him before , the Commissions table is indication of what products seller can sell
Thanks in advance
SELECT sellableProduct
FROM (SELECT Comissions.ProductId AS sellableProduct, Sellers.SellerId AS sellableSeller FROM Comissions INNER JOIN Sellers ON Comissions.SellerId=Sellers.SellerId INNER JOIN Customers ON Sellers.SellerId=Customers.SellerId WHERE Customers.CustomerId = #customerid) AS tblSellable
LEFT JOIN (SELECT Sales.ProductId AS soldProduct, Customers.SellerId as soldSeller FROM Customers INNER JOIN Sales ON Customers.CustomerId=Sales.CustomerId WHERE Customers.CustomerId = #customerid) AS tblSold
ON tblSellable.sellableProduct=tblSold.soldProduct AND tblSellable.sellableSeller=tblSold.soldSeller
WHERE tblSold.soldProduct IS NULL
this way you avoid time-consuming IN statements
If a Customer can only have one Seller, then you can omit the seller link:
SELECT sellableProduct
FROM (SELECT Comissions.ProductId AS sellableProduct FROM Comissions INNER JOIN Sellers ON Comissions.SellerId=Sellers.SellerId INNER JOIN Customers ON Sellers.SellerId=Customers.SellerId WHERE Customers.CustomerId = #customerid) AS tblSellable
LEFT JOIN (SELECT Sales.ProductId AS soldProduct FROM Sales WHERE Sales.CustomerId = #customerid) AS tblSold
ON tblSellable.sellableProduct=tblSold.soldProduct
WHERE tblSold.soldProduct IS NULL
Basically, you're looking for products that have a record in commissions, but not in sales. Using :id to denote the specific ID:
SELECT *
FROM products
WHERE productid IN (SELECT productid
FROM commissions
WHERE sellerid = :id) AND
productid NOT IN (SELECT productid
FROM sales
JOIN customers ON sales.customerid = cusomers.customerid
WHERE sellerid = :id)
Would this work?
SELECT sell.*, prod.* FROM
Sellers sell
INNER JOIN Customers cust ON cust.SellerId = sell.SellerId
LEFT JOIN Commissions comm ON sell.SellerId = comm.SellerId
LEFT JOIN Products prod ON prod.ProductId = comm.ProductId
WHERE prod.ProductId NOT IN (
SELECT ProductId
FROM Products p INNER JOIN
Sales s ON s.ProductId = p.ProductId
WHERE s.CustomerId = #CustomerId
It get all the sellers and the respective product from commission, where the product Id is NOT associated with any sale of the client
I just took a final exam and one of the questions asked me to double join three tables, and report the max sale payout for each salesperson.
The tables have the following variables:
Salesperson(id, name)
Order(orderid, order_date, Cust_id, Saleperson_id, amount)
Customer(id, name)
After joining:
select salesperson.Name, Orders.Number, customer.Name, Orders.Amount
from Orders
join salesperson
on orders.Salesperson_id = salesperson.ID
join Customer
on customer.ID = orders.cust_id
What the instructed wanted was for me to find each salesperson's maximum sell (as found by order.amount). He also wanted the salesperson (salesperson.name), the order number of the max sale (orders.number), the customer the sale was with (customer.name), and the max sale amount. What is the most efficient way to do this problem? I have tried to use "group by salesperson.name", but I cannot because the orders.number and customer.name are never held in the aggregation.
I finished the problem this way
select
salesperson.name as Sales_Person,
orders.number as Order_Number,
customer.Name as Customer_Name,
orders.Amount as Sale_Amount
from salesperson
left join Orders
on salesperson.ID = orders.Salesperson_id
left join Customer
on orders.cust_id = customer.ID
where orders.Amount in (select max(orders.Amount)
from salesperson
join Orders
on salesperson.ID = orders.Salesperson_id
join Customer
on orders.cust_id = customer.ID
group by salesperson.name)
I know this is a bad way to do it. For instance, what if two different salesperson's max sale was equivalent? Max and min are not like count and sum because it is picking out one line from a aggregation, but the rules still apply. Also, you might notices that there is no real unique identifier in the joined table other than order.number which is not useful. Therefore, I would have to use some composite of salesperson.name and order.number.
Also, what do I do if I have to pick the top three sales for each salesperson? Should such an output be totally different code-wise than what would be required from just the first sale?
I keep bumping me head against this problem, and I would love to have a more professional approach to this problem.
SELECT
M.max_amount,
S.Name,
O.Number,
C.Name
FROM orders O
JOIN salesperson S
ON S.Salesperson_id = O.Salesperson_id
JOIN customer C
ON C.Customer_id = O.Customer_id
JOIN (
SELECT Salesperson_id, MAX(amount) max_amount
FROM Order
GROUP BY Salesperson_id
) M
ON M.Salesperson_id = O.Salesperson_id AND M.max_amount = O.amount
For the top 3:
SELECT
M.Amount,
S.Name,
O.Number,
C.Name
FROM orders O
JOIN salesperson S
ON S.Salesperson_id = O.Salesperson_id
JOIN customer C
ON C.Customer_id = O.Customer_id
CROSS APPLY (
SELECT TOP 3 Amount
FROM Order
WHERE Salesperson_id = O.Salesperson_id
ORDER BY Amount DESC
) M
Here is how I contructed the step-by-step:
M1. create a sub-query that will return CustomerId and total invoiced for that customer
M2. A second subquery that will give a list of distinct ProductIDs (along with product SKUs) and CustomerIDs.
M3. The M1 and M2 subqueries will be joined to make association between customer totals and products (for the same CustomerId).
M4. The query M3 will be fed to the final query that will just find the top 5 products.
I'm stuck on creating the distinct ProductID and customerID because they would have to be in aggregate functions in order to make them distinct.
Attached is an image that is the erwin diagram which helps understand the system.
If you can help me with M1-M4, I will greatly appreciate it. I'm not a programmer by trade but a business analyst.
--M1--
select C.CustomerId, COUNT(I.InvoiceId) TotalNumInvoices
from Customer C
JOIN Invoice I ON (I.CustomerId = C.CustomerId)
group by C.CustomerId
--M2: Incomplete--
select P.ProductID, P.SKU, C.CustomerID
from Product P
JOIN InvoiceLine IL ON (IL.ProductId = P.ProductId)
JOIN Invoice I ON (IL.InvoiceId = I.InvoiceId)
JOIN Customer C ON (C.CustomerId = I.CustomerId)
you can also use the DISTINCT keyword your select clause in order to get unique values. Try this for m2:
select DISTINCT p.productID, p.sku, i.customerID
from invoice i INNER JOIN invoiceLine il
ON i.invoiceID = il.invoiceID
JOIN product p
ON il.productID = p.productID;
I have a table for "branches", "orders" and "products. Each order and product are connected to a branch with branch_id. I need an sql statement to get a list of all branches with a field for how many orders and a field for how many products.
This works:
SELECT b.*, COUNT(o.id) AS orderCount FROM branches b
LEFT JOIN orders o ON (o.branch_id = b.id) GROUP BY b.id
but it only gets the amount of orders, not products.
If I change it to add amount of products, the amounts are wrong because it's getting amount of orders * amount of products.
How can I get the amount of both the orders and the products in the same SQL statement?
Something like this should work (on sql server at least - you didn't specify your engine).
SELECT
b.id
,COUNT(distinct o.id) AS orderCount
,COUNT(distinct p.id) AS productCount
FROM branches b
LEFT JOIN orders o
ON (o.branch_id = b.id)
left join products p
on p.product_id=b.id)
GROUP BY
b.id
Please try:
select
*,
(select COUNT(*) from Orders o where o.branch_id=b.id) OrderCount,
(select COUNT(*) from Products p where o.branch_id=p.id) ProductCount
From
branches b
I'm trying to find a simple MySQL statement for the following two problems:
I have 4 tables: Employees, Customers, Orders, Products (Each entry in Orders contains a date, a reference one product, a quantity and a reference to a customer, and a reference to an Employee).
Now I'm trying to get all customers where the volume of sale (quantity * product.price) is bigger in 1996 than in 1995.
And: I want to list all Employees whose volume of sale is below the average volume of sale.
Any help would really be appreciated. I've managed to get the information using a php script but I think this can be done with some clever SQL Statements.
Can anybody help me?
Employee Table: ID# Name
Products Table: ID# NAME# PRICE
Orders Table: ODERID# CUSTOMERID # DATE # EMPLOYEE# PRODUCTID# QUANTITY
For the first part (assuming quite a bit about the schema):
SELECT Customers.ID
FROM Customers
LEFT JOIN orders AS o1 ON o1.CustomerID=Customers.ID AND YEAR(o1.DATE) = 1995
LEFT JOIN products AS p1 ON p1.id = o1.productID
LEFT JOIN orders AS o2 ON o2.CustomerID=Customers.ID AND YEAR(o2.DATE) = 1996
LEFT JOIN products AS p2 ON p2.id = o2.productID
HAVING SUM(o1.quantity* p1.price) < SUM(o2.quantity*p2.price)
I don't know the database type you're using, so I'll use sqlserver. The 'Year' function is available on most databases, so you should be able to rewrite the query for your db in question.
I think this is the query which returns all customerid's + ordertotal for the customers which have a higher total in 1996 than in 1995, but I haven't tested it. Crucial is the HAVING clause, where you can specify a WHERE kind of clause based on the grouped result.
SELECT o.CustomerId, SUM(o.Quantity * p.Price) AS Total
FROM Orders o INNER JOIN Products p
ON o.ProductId = p.ProductId
WHERE YEAR(o.Date) == 1996
GROUP BY o.CustomerId
HAVING SUM(o.Quantity * p.Price) >
(
SELECT SUM(o.Quantity * p2.Price) AS Total
FROM Orders o2 INNER JOIN Products p2
ON o2.ProductId = p.ProductId
WHERE YEAR(o.Date) == 1995
AND o2.CustomerId = o.CustomerId
GROUP BY o.CustomerId
)
something like that:
select * from customers c
where (select sum (o.quantity * p.price) from orders o, product p where o.productID = p.productID and o.dateyear = 1996 and o.customerID = c.customerID) < (select sum (o.quantity * p.price) from orders o, product p where o.productID = p.productID and o.dateyear = 1995 and o.customerID = c.customerID)
select * from employees e where (select avg (o.quantity * p.price) from orders o, product p where o.productID = p.productID and o.empID = e.EmpID) < (select avg (o.quantity * p.price) from orders o, product p where o.productID = p.productID)