Sorry new to this but,
I need to sort customer names by total quantity of items purchased by them, in desc order.
the purchased amount in the table is known as Inv_number
I would need the customer name and than the sum. This is what it should be
Thanks
I don't know what your tables are named or what fields they have on them, so I'll give a generic example:
SELECT c.CUST_NAME AS "cust_name",
SUM(oi.QTY_PURCHASED) AS "sum"
FROM CUSTOMERS c
INNER JOIN ORDERS o
ON o.ID_CUSTOMERS = c.ID_CUSTOMERS
INNER JOIN ORDER_ITEMS oi
ON oi.ID_ORDERS = o.ID_ORDERS
GROUP BY c.CUST_NAME
ORDER BY SUM(oi.QTY_PURCHASED) DESC,
c.CUST_NAME ASC
db<>fiddle here
Should work this way - you have to join the tables for customerinfo (customer in this script) and the items purchased (order_items). For simplicity I only made an example with two tables. if the customer_id is present in a kind of "order" table, you have to join order_items -> order -> customer
SELECT
x.customer_name,
y.customer_amount
FROM customer x
INNER JOIN (
SELECT
customer_id,
SUM(order_amount) AS customer_amount
FROM order_items
GROUP BY customer_id
) y ON x.id = y.customer_id
ORDER BY y.customer_amount DESC;
Related
I have these 3 tables with the following structures:
Products
product_id | category_id | product_name
Customers
customer_id | customer_name
Orders
order_id | customer_id | product_id
I need to write a SQL query that will print the top customers regarding the number of categories they have bought products from (the best customer is the one that has bought from the most categories).
Can anyone show me how to do that?
I tried like this, but I get the following error "not a GROUP BY expression":
select
(select customer_name
from customers
where customers.customer_id = orders.customer_id) as name,
(select count(category_id)
from products
where products.product_id = orders.product_id)
from
orders
group by
customer_id
order by
count(customer_id) desc;
I managed to make the top regarding how many products the customers bought. The solution I used is:
select
(select customer_name from customers
where customers.customer_id = orders.customer_id) as name,
count(product_id) as "number of ordered products"
from
orders
group by
customer_id
order by
count(product_id) desc;
Nested queries for this? Sheesh...
Just join them already.
And then order by the unique categories
SELECT c.customer_name
, COUNT(DISTINCT p.category_id) AS TotalOrderedCategories
FROM Orders o
LEFT JOIN Customers c ON c.customer_id = o.customer_id
LEFT JOIN Products p ON p.product_id = o.product_id
GROUP BY c.customer_name
ORDER BY COUNT(DISTINCT p.category_id) DESC
Then depending on your RDBMS flavor, add a TOP or a LIMIT.
Need help with a query to returns each individuals most recent order, date of the order, number of products in the order and the total amount. I am kind of stuck trying to get the number of products and total.
Here are the table diagrams
Not sure if I should be using multiple joins or subqueries:
SELECT FirstName, LastName, MAX(O.OrderDate), O.OrderDate
FROM Customer C
INNER JOIN Order O ON C.CustomerID = O.CustomerID
It is always good practice to start from assumed dim tables such as product.This Query should help. It is better to aggregate quantity and amount to get results at aggregate level
SELECT FirstName
,LastName
,max(o.orderdate) Orderdate
,Sum(Quantity) Quantity
,Sum(TotalAmount) TotalAmount
FROM Product p
INNER JOIN Orderitem oi
ON Oi.product_id = p.id
INNER JOIN
ORDER o
ON o.id = oi.order_id
INNER JOIN Customer c
ON c.id = o.Customer_id
GROUP BY FirstName
,LastName
not sure if you want aggregations but here you go:
SELECT customer.firstname, customer.lastname, COUNT(DISTINCT orderitem.productid), [order].totalamount
FROM [order] LEFT JOIN customer ON [order].customerid=customer.id LEFT JOIN orderitem ON order.id=orderitem.orderid
WHERE [order].date=MAX([order].date)
GROUP BY customer.firstname,customer.lastname, [order].totalamount
Still don't know why you are applying a where clause for the last order, it's up to you to keep or not the where condtion.
I have three tables, orders, orders_details and customers. I need to select orders by one customer for the orders table so I did this
orders columns:
id
customer_id
created
vat
discount
amount
paid
orders_details columns:
id
order_id
cost
qty
product
The SQL I used
SELECT
orders.*,
SUM(orders_details.qty*orders_details.cost) as amount,
SUM(orders_details.qty) AS qty
FROM
orders,
orders_details,
customers
WHERE
orders.customer_id = customers.id
AND orders_details.order_id = orders.id
AND orders.customer_id = 1
but I am getting a wrong qty of 30 instead of 20 and the amount is wrong
If you want to aggregate per order you need a GROUP BY clause. Also you should use proper JOIN syntax, and might consider using aliases to make the query more compact.
SELECT
o.*,
SUM(od.qty * od.cost) AS amount,
SUM(od.qty) AS qty
FROM orders o
INNER JOIN orders_details od ON od.order_id = o.id
INNER JOIN customers c ON o.customer_id = c.id -- not used, might be excluded
WHERE o.customer_id =1
GROUP BY o.id
Depending on what database system you are using you might need to include all columns referenced in o.* in the GROUP BY:
GROUP BY o.id, o.customer_id, o.created, o.vat, o.discount, o.amount, o.paid
Last note: as you don't seem to use any data from the customers table you probably could exclude that table altogether.
You're missing a GROUP BY clause which I'm guessing should be on orders.id.
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
I am using three tables in a PostgreSql database as:
Customer(Id, Name, City),
Product(Id, Name, Price),
Orders(Customer_Id, Product_Id, Date)
and I want to execute a query to get from them "the customers that have have ordered at least two different products alnong with the products". The query I write is:
select c.*, p.*
from customer c
join orders o on o.customer_id = c.id
join product p on p.id = o.product_id
group by (c.id)
having count(distinct o.product_id)>=2
It throws the error:
"column "p.id" must appear in the GROUP BY clause or be used in an aggregate function
LINE 1: select c.*, p.*".
However if I remove the the p.* from select statement (assuming that I one does not want the products, only the customers), it runs fine. How can I get the products as well?
Update: Having ordered two or more products, a customer must appear on the output as many times as its product he has ordered. I want as output a table with 5 columns:
Cust ID | Cust Name | Cust City | Prod ID | Prod Name | Prod Price
Is it possible in SQL given that group by should be used? Shoul it be used on more than one columns on different tables?
Try this out :
SELECT distinct c.* ,p.*
FROM Customer c
JOIN
(SELECT o.customer_id cid
FROM Product P
JOIN Orders o
ON p.id= o.product_id
GROUP BY o.customer_id
HAVING COUNT(distinct o.product_id)>=2) cp
ON c.id =cp.cid
JOIN Orders o
on c.id=o.customer_id
JOIN Product p
ON o.product_id =p.id
I hope it solves your problem.
I think you can use following query for this question -
SELECT C1.*, p1.*
FROM Customer C1
JOIN Orders O1 ON O1.Customer_Id = C1.Id
JOIN Product P1 ON P1.Id = O1.Product_Id
WHERE C1.Id IN (SELECT c.Id
FROM Customer c
JOIN Orders o ON o.Customer_Id = c.Id
GROUP BY (c.Id)
HAVING COUNT(DISTINCT o.Product_Id) >= 2)