Access Query from multiple tables - sql

I currently have an Access Database with a few tables, among them Order, OrderDetails and Client.
Order (OrderID, TimeStamp, FKEmployeeID, FKClientID, OrderStatus, Comments)
OrderDetails (OrderDetailsID, FKOrderID, FKProductID, Quantity, Cost, Total Cost)
Client (ClientID, Name)
I'm trying to build a query where I can get the total orders that a client has made and the total Items.
Example:
Customer, Total Orders, Total Items
John, 5, 15
Alex, 2, 30
Ana, 1, 3
Whenever I try to make a query Total Orders and Total Items give me the same number.
Any help would be greatly appreciated!

This is supported even by ms access:
SELECT c.Name,
(select count(*)
from Orders o
where o. FKClientID = C.ClientID) as [Total Orders],
(select sum(Quantity) as Items
from OrderDetails od
inner join Order o on o.OrderID = od.FKOrderID
where o.FKClientId = C.ClientID) as [Total Items]
from Client c;

Unfortunately, MS Access doesn't support COUNT(DISTINCT). You can do this with two aggregations:
SELECT c.[Name], COUNT(*) As NumOrders, SUM(o.NumItems) As NumItems
FROM Client as c INNER JOIN
(SELECT o.OrderID, o.FKClientID, COUNT(*) As NumItems
FROM [Order] as o INNER JOIN
OrderDetails as od
ON od.FKOrderID = o.OrderID
GROUP BY o.OrderID, o.FKClientID
) as o
ON o.FKClientID = c.ClientId
GROUP BY c.ClientId, c.Name;

What about this solution (clients without orders are left out hereby):
SELECT Client.[Name],
Count(myTotalItems.OrderID) As TotalOrders,
Sum(myTotalItems.TotalItems) As TotalItems
FROM Client,
(SELECT First([Order].OrderID) As OrderID,
First([Order].FKClientID) As
ClientID,
Count(OrderDetails.OrderDetailsID) As TotalItems
FROM [Order], OrderDetails
WHERE OrderDetails.FKOrderID like [Order].OrderID
GROUP BY [Order].OrderID) As myTotalItems
WHERE myTotalItems.ClientID like Client.ClientID
GROUP BY Client.[Name];

It would be easier for you if you divide the task into multiple queries. I am giving the sample using Northwind database, you can test and see on it. Note that the structures and fieldnames are very similar to yours.
First create one that gets ClientId, OrderId, OrderDate and Sum of Quantity.
SELECT c.CustomerId, o.OrderId, o.OrderDate, sum(od.Quantity) AS Qty
FROM (Customers AS c INNER JOIN Orders AS o ON c.CustomerId = o.CustomerId)
INNER JOIN [Order Details] AS od ON o.OrderId = od.OrderID
GROUP BY c.CustomerId, o.OrderId, o.OrderDate;
Save this as "OrderOfClients" (it would be saved in Queries). Next create a query that uses this one and asks for date range:
SELECT c.CustomerId, c.CompanyName,
Count(*) AS [Total Orders],
Sum(Qty) AS [Total Items]
FROM Customers AS c
INNER JOIN OrdersOfClients AS co ON c.CustomerId = co.CustomerId
WHERE co.OrderDate Between [#startDate] And [#endDate]
GROUP BY c.CustomerId, c.CompanyName;
You can save this one as "OrdersOfClientsSummary" and call for your report.
PS: In my personal opinion, if you use a database other than access you would be doing yourself a big favor.

Related

sql use aggregate function that counts a unique value with group by using inner joins

I searched and found similar questions online but not my particular one, they all use where or having clause.If theres one similar to mine please link it. It's a 2 part question and I have the first one done. Thank you in advance.
Okay so heres the question, part 1
"Find by customer, the total cost and the total discounted cost for each product on the order ?".
It also asks to use inner joins to find the customer and order it a specific way. Below is the answer.
SELECT
C.companyname, O.orderid, O.orderdate, P.productname,
OD.orderid, OD.unitprice, OD.qty, OD.discount,
(OD.unitprice * OD.qty - (OD.qty * OD.discount)) AS TotalCost,
(OD.qty * OD.discount) AS TotalDiscountedCost
FROM
Sales.Customers AS C
INNER JOIN
Sales.Orders AS O ON C.custid = O.custid
INNER JOIN
Sales.OrderDetails OD ON O.orderid = OD.orderid
INNER JOIN
Production.Products as P ON OD.productid = P.productid
ORDER BY
C.companyname, O.orderdate;
Now the second question is to
follow up and resume the first one by "customer and the order date year, the total cost and the total discounted cost on the order ?". It also asks for this, "Project following columns in the select clause as.
GroupByColumns.companyname
GroupByColumns.OrderdateYear
AggregationColumns.CountNumberOfIndividualOrders
AggregationColumns.CountNumberOfProductsOrders
AggregationColumns.TotalCost
AggregationColumns.TotalDiscountedCost
Finally to order by company name and orderdateYear( which are groups). Where im stuck is how to count the specific orders of qty that equal 1 as an aggregate function in the SELECT clause. I know it has to use the aggregate function COUNT because of the GROUP BY, just don't know how to. This is what I have.
SELECT
C.companyname, YEAR(O.orderdate) AS orderyear,OD.qty,
-- Where in the count function or if theres another way do I count all the
--single orders
--COUNT(OD.qty) AS indiviualorders,
(OD.unitprice * OD.qty - (OD.qty * OD.discount)) AS TotalCost,
(OD.qty * OD.discount) AS TotalDiscountedCost
FROM
Sales.Customers AS C
INNER JOIN
Sales.Orders AS O ON C.custid = O.custid
INNER JOIN
Sales.OrderDetails OD ON O.orderid = OD.orderid
INNER JOIN
Production.Products as P ON OD.productid = P.productid
GROUP BY
C.companyname, YEAR(O.orderdate)
ORDER BY
C.companyname, O.orderdate;
You case use a case statement inside a sum
SUM(CASE WHEN <xyz> THEN 1 ELSE 0 END)
But for the count of unique orders, use SELECT(DISTINCT ) on a key that is unique in the order table
SELECT COUNT(DISTINCT O.OrderID) As DistinctOrders FROM Table

Stuck doing a common table expression to calculate total orders for each product category using NORTHWND

Guys so as part of my job as a Data Support Analyst I am training up to become a software developer, my mentor gave me a group of test statements and this one seems way more advanced than anything I have done previously. The question is...
*
6) Write a subquery or common table expression to calculate total
orders for each product category. that will Write a query that will
bring back each product name, the total number of orders made for the
product and join to the subquery or CTE to calculate the percentage
of sales that product represents of its product category. For example,
if Category of Soaps has 2 products; Blue Soup and Red Soap, blue soup
had 40 orders and red soaps had 10 orders I would expect to see the
following rows: Product Name Total Orders % of Category Red
Soap 40 80%
Blue Soap 10 20%
*
So far I have managed to get the following but I'm struggling to progress past this...
;WITH [Products] (CategoryId, TotalNumberOfOrders)
AS (
SELECT p.CategoryId,
COUNT (OD.OrderID) as TotalNumberOfOrders
FROM [dbo].[Products] p
INNER JOIN [dbo].[Order Details] OD
ON p.ProductID=OD.ProductID
GROUP BY p.CategoryId )
SELECT * From Products
Any help would be fantastic! ( I'm using NORTHWND database btw)
I think what you need is
;WITH temp AS
(
SELECT p.CategoryId,
COUNT (DISTINCT OD.OrderID) as TotalNumberOfOrders
FROM [dbo].[Products] p
INNER JOIN [dbo].[Order Details] OD ON p.ProductID=OD.ProductID
GROUP BY p.CategoryId
)
SELECT p.ProductName,
Count(DISTINCT Od.OrderId) AS Total,
Count(DISTINCT Od.OrderId)*100/temp.TotalNumberOfOrders AS Percentage
FROM Products p
INNER JOIN [dbo].[Order Details] OD ON p.ProductId = OD.ProductId
INNER JOIN temp ON p.CategoryId = temp.CategoryId
GROUP BY p.ProductId, p.ProductName, temp.TotalNumberOfOrders
Remember Count(Distinct..) to count Order.
Using a sub-Query:
SELECT P.ProductName,
COUNT(OrderID) AS NumberOfOrders,
CAST((CAST(COUNT(OrderID) AS DECIMAL(9,2)) / CAST(Derived_Table.CNT AS
DECIMAL(9,2))) * 100 AS DECIMAL(9,2)) AS Percentage
FROM [Northwind].[dbo].[Order Details]
INNER JOIN dbo.Products AS P
ON [Order Details].ProductID = P.ProductID
INNER JOIN (SELECT COUNT(F.OrderID) AS CNT, P.CategoryID
FROM [Northwind].[dbo].[Order Details] F
INNER JOIN dbo.Products P
ON F.ProductID = P.ProductID
GROUP BY P.CategoryID) AS Derived_Table
ON P.CategoryID = Derived_Table.CategoryID
GROUP BY [Order Details].ProductID, P.ProductName, Derived_Table.CNT
ORDER BY [Order Details].ProductID

SQL Server : How to Select Sum Amount Spent for the Most Expensive Item by a Customer - Northwind DB

Actually question tells all; Lots of customers has many orders with for many items; I'm trying to display the total amount spent for the most expensive item ordered by that customers through the all orders given by that customer. I'm using Northwind DB and tables like Customers, Orders, Order Details, Products. I've the query below, I've tried to limit it by an aggregate function but SQL does not allow it on where clause. Any help?
select
p.ProductName,
c.ContactName,
od.ProductID,
MAX(od.UnitPrice)
SUM(od.UnitPrice*od.Quantity) as Total
from
Customers c
join
Orders o ON c.CustomerID = o.CustomerID
join
[Order Details] od on od.OrderID = o.OrderID
join
Products p on od.ProductID = p.ProductID
where
c.CustomerID in
group by
c.ContactName, p.ProductName, od.Quantity, od.ProductID
order by
MAX(od.UnitPrice) desc
I think the easiest way to solve this is by using a window function to get the highest priced product. The following query uses row_number() for this purpose:
select p.ProductName, c.ContactName, od.ProductID,
MAX(od.UnitPrice)
SUM(od.UnitPrice*od.Quantity) as Total
from Customers c join
(select od.*, o.CustomerId,
row_number() over (partition by o.CustomerId
order by od.UnitPrice desc) as seqnum
from [Order Details] od join
Orders o
on od.OrderId = o.OrderId
) od
on od.CustomerId = c.CustomerId and seqnum = 1 join
Products p
on od.ProductID = p.ProductID
group by c.ContactName, p.ProductName, od.ProductID
order by MAX(od.UnitPrice) desc;
Note that the joins have been rearranged a bit. You need the customer id to define the highest priced product in the subquery, so the subquery has the join to orders. You don't need the join in the outer query.

Does this SQL statement require a nested SELECT query?

Here is what I have so far but the results are wrong.
SELECT c.CompanyName,
COUNT(o.OrderID) AS [Total Orders],
SUM(
(od.UnitPrice -
(od.UnitPrice * od.Discount))* Quantity) AS [Purchase Total]
FROM Customers AS c,
Orders AS o,
[Order Details] AS od
WHERE c.CustomerID = o.CustomerID
AND o.OrderID = od.OrderID
GROUP BY c.CompanyName
ORDER BY c.CompanyName;
The issue I am having is with the count, it is off by double or more. I believe that this is because the OrderID appears multiple times in the Order Details table. I think I need a nested SELECT statement but I am unsure how to do that.
Would I be removing the SUM() expression, Order Details, and the AND clause from the first query? Or am I way off?
With help I have gotten the COUNT field to work but now my SUM field is wrong. This is my most recent attempt and it produces the same value for every customer.
SELECT c.CompanyName,
COUNT(o.OrderID) AS [Total Orders],
(SELECT SUM(
(odIN.UnitPrice -
(odIN.UnitPrice * odIN.Discount)) * odIN.Quantity) AS [OrderTotal]
FROM [Order Details] AS odIN, Orders As oIN
WHERE odIN.OrderID = oIN.OrderID) AS [Purchase Total]
FROM
Customers AS c, Orders AS o
WHERE c.CustomerID = o.CustomerID
GROUP BY c.CompanyName
ORDER BY c.CompanyName;
I was unsuccessful at getting the query to fully work the way I wanted it to. Then I realized that maybe maybe I was looking for the wrong data. So I switched the name for the COUNT field to Num Products Purchased.
I would still like to get the other way working, but I think that will require creating a temporary table or view that could be used to do one of the calculations and then call it from the query. That is something I'll have to figure out.
Thank you for the attempts to help.
Because Access doesn't have COUNT(DISTINCT) then you need to create an inner query.
What this does is compute the sum of each item in an order in the inner query, and then sums up all the order totals for the customer as the purchase total. An individual OrderID will not be counted twice, as o and od now have a one to one relationship.
There might be a syntax error in there somewhere, but the idea should work.
SELECT c.CompanyName,
COUNT(o.OrderID) AS [Total Orders],
SUM(od.OrderTotal) AS [Purchase Total]
FROM
Customers AS c,
Orders AS o,
(SELECT odIn.OrderID,
SUM(
(odIn.UnitPrice -
(odIn.UnitPrice * odIn.Discount)) * odIn.Quantity) AS [OrderTotal]
FROM [Order Details] AS odIn
GROUP BY odIn.OrderID) AS od
WHERE c.CustomerID = o.CustomerID
AND o.OrderID = od.OrderID
GROUP BY c.CompanyName
ORDER BY c.CompanyName;
if the problem is because OrderID appears multiple times, try:
SELECT c.CompanyName, COUNT(DISTINCT o.OrderID) AS [Total Orders], SUM((od.UnitPrice - (od.UnitPrice * od.Discount)) * Quantity) AS [Purchase Total]
FROM Customers AS c, Orders AS o, [Order Details] AS od
WHERE c.CustomerID = o.CustomerID AND o.OrderID = od.OrderID
GROUP BY c.CompanyName
ORDER BY c.CompanyName;
The distinct clause lets you count only each appearance.
First I would like to thank Daniel for his help. I did finally get the query to work with help from another source. Daniel's solution is better as it requires less code and even formats the sum in currency.
Here is the one I got to work:
SELECT vtOrdCnt.*, ROUND(vtTotCost.PurchaseTotal, 2) AS [Purchase Total]
FROM
(
SELECT CustomerID, COUNT(OrderID) AS TotalOrders
FROM orders
GROUP BY CustomerID
) AS vtOrdCnt,
(
SELECT CustomerID, SUM(UnitPrice * (1-Discount)*Quantity) AS PurchaseTotal
FROM Orders AS o, [Order Details] AS od
WHERE o.orderID = od.orderID
GROUP BY CustomerID
) AS vtTotCost
WHERE vtOrdCnt.CustomerID = vtTotCost.CustomerID
ORDER BY vtOrdCnt.CustomerId
By using Aliases and two select statements in the FROM clause it allowed the query to function the way I wanted it to.

SQL Query for counting number of orders per customer and Total Dollar amount

I have two tables
Order with columns:
OrderID,OrderDate,CID,EmployeeID
And OrderItem with columns:
OrderID,ItemID,Quantity,SalePrice
I need to return the CustomerID(CID), number of orders per customer, and each customers total amount for all orders.
So far I have two separate queries. One gives me the count of customer orders....
SELECT CID, Count(Order.OrderID) AS TotalOrders
FROM [Order]
Where CID = CID
GROUP BY CID
Order BY Count(Order.OrderID) DESC;
And the other gives me the total sales. I'm having trouble combining them...
SELECT CID, Sum(OrderItem.Quantity*OrderItem.SalePrice) AS TotalDollarAmount
FROM OrderItem, [Order]
WHERE OrderItem.OrderID = [Order].OrderID
GROUP BY CID
I'm doing this in Access 2010.
You would use COUNT(DISTINCT ...) in other SQL engines:
SELECT CID,
Count(DISTINCT O.OrderID) AS TotalOrders,
Sum(OI.Quantity*OI.SalePrice) AS TotalDollarAmount
FROM [Order] O
INNER JOIN [OrderItem] OI
ON O.OrderID = OI.OrderID
GROUP BY CID
Order BY Count(DISTINCT O.OrderID) DESC
Which Access unfortunately does not support. Instead you can first get the Order dollar amounts and then join them before figuring the order counts:
SELECT CID,
COUNT(Orders.OrderID) AS TotalOrders,
SUM(OrderAmounts.DollarAmount) AS TotalDollarAmount
FROM [Orders]
INNER JOIN (SELECT OrderID, Sum(Quantity*SalePrice) AS DollarAmount
FROM OrderItems GROUP BY OrderID) AS OrderAmounts
ON Orders.OrderID = OrderAmounts.OrderID
GROUP BY CID
ORDER BY Count(Orders.OrderID) DESC
If you need to include Customers that have orders with no items (unusual but possible), change INNER JOIN to LEFT OUTER JOIN.
Create a query which uses your 2 existing queries as subqueriers, and join the 2 subqueries on CID. Define your ORDER BY in the parent query instead of in a subquery.
SELECT
sub1.CID,
sub1.TotalOrders,
sub2.TotalDollarAmount
FROM
(
SELECT
CID,
Count(Order.OrderID) AS TotalOrders
FROM [Order]
GROUP BY CID
) AS sub1
INNER JOIN
(
SELECT
CID,
Sum(OrderItem.Quantity*OrderItem.SalePrice)
AS TotalDollarAmount
FROM OrderItem INNER JOIN [Order]
ON OrderItem.OrderID = [Order].OrderID
GROUP BY CID
) AS sub2
ON sub1.CID = sub2.CID
ORDER BY sub1.TotalOrders DESC;