I have two tables: Customers and Orders. I do a left join of Customers and Orders on CustomerID column which is primary key in Customers and foreign key in Orders.
When I list CustomerID after joining, I get the list as expected.
When I count the number of CustomerID, again I get the number of record I am expecting.
When I use distinct count for CustomerID, i get an error.
1.
select Customers.CustomerID as list
from Customers left join Orders on Customers.CustomerID = Orders.CustomerID
where Customers.CustomerID = 4;
2.
select count(Customers.CustomerID) as numRecord
from Customers left join Orders on Customers.CustomerID = Orders.CustomerID
where Customers.CustomerID = 4;
3.
select count(distinct (Customers.CustomerID)) as numRecord
from Customers left join Orders on Customers.CustomerID = Orders.CustomerID
where Customers.CustomerID = 4;
I cannot understand where is the error. Any help would be appreciated.
The error:
Error in SQL:
Syntax error (missing operator) in query expression 'count(distinct Customers.CustomerID)'.
You don't need the () around Customers.CustomerID in count(distinct ..)
select count(distinct Customers.CustomerID) as numRecord
from Customers
left join Orders on Customers.CustomerID = Orders.CustomerID
where Customers.CustomerID = 4;
Related
I have two tables, orders and customers, and I am trying to return the customerID and name of customers with no orders.
customers
customerID: integer
name: string
orders
orderID: integer
itemID: integer
customerID: integer
date: date
What I currently have is not returning any results:
SELECT customers.customerID, customers.fName, orders.date
FROM orders INNER JOIN customers
ON orders.customerID = customers.customerID
GROUP BY orders.customerID
HAVING COUNT(*) = 0
You need a LEFT OUTER JOIN to accomplish this:
SELECT customers.customerID, customers.fName
FROM customers LEFT OUTER JOIN orders on customers.customerID = orders.customerID
WHERE orders.customerID IS NULL
How do i use DISTINCT command in a SQL query to show the supplier id, company name, and the number of distinct products from that supplier that were ordered prior to a specific date? I ran the code in Access but it doesn't translate over to SQL efficiently. The table appears.
[Supplier ID Company Name Product Name Order Date
1 Exotic Liquids Chang 17-Aug-94
1 Exotic Liquids Chang 22-Nov-94
1 Exotic Liquids Aniseed Syrup 26-Sep-94]
The code I have so far is the following. Where I get confused is where to put the DISTINCT statement. Should it be immediately after the Select? Should it go in Parentheses in addition to the SELECT? Excuse my lack of knowledge on this subject in advance.
SELECT Suppliers.SupplierID, Customers.CompanyName, Products.ProductName,
Orders.OrderDate
FROM Suppliers INNER JOIN
Products ON Suppliers.SupplierID = Products.SupplierID CROSS JOIN
Customers INNER JOIN
Orders ON Customers.CustomerID = Orders.CustomerID
WHERE Orders.OrderDate <='1/1/1999'
ORDER BY Suppliers.SupplierID
You can either distinct by all columns selected :
SELECT DISTINCT
Suppliers.SupplierID, Customers.CompanyName, Products.ProductName,
Orders.OrderDate
FROM
Suppliers INNER JOIN
Products ON Suppliers.SupplierID = Products.SupplierID CROSS JOIN
Customers INNER JOIN
Orders ON Customers.CustomerID = Orders.CustomerID
WHERE
Orders.OrderDate <='1/1/1999'
ORDER BY
Suppliers.SupplierID
or use group by instead if you need to distinct only by SupplierID. DISTINCT is not a function, hence DISTINCT(Suppliers.SupplierID) means the same as simply put DISTINCT word after SELECT in this case (see the 2nd reference below).
For Reference :
http://blog.sqlauthority.com/2007/12/20/sql-server-distinct-keyword-usage-and-common-discussion/
http://weblogs.sqlteam.com/jeffs/archive/2007/10/12/sql-distinct-group-by.aspx
I'm pretty sure it's this:
SELECT DISTINCT(Suppliers.SupplierID), Customers.CompanyName, Products.ProductName,Orders.OrderDate
FROM Suppliers INNER JOIN
Products ON Suppliers.SupplierID = Products.SupplierID CROSS JOIN
Customers INNER JOIN
Orders ON Customers.CustomerID = Orders.CustomerID
WHERE Orders.OrderDate <='1/1/1999'
ORDER BY Suppliers.SupplierID
I am counting how many times a company has ordered. Then I am only showing if a company has ordered less than 5 times. I am then checking it against the table with all company names to see what company has not ordered, which would not show up on the order table, then add their name on the displayed list.
What I have tried:
Select Orders.CustomerID, Count(Orders.CustomerID) AS OrderCount
From Orders Left Join Customers
On Orders.CustomerID = Customers.CustomerID
Group By Orders.CustomerID
Having Count(Orders.CustomerID) <5
This is totally wrong:
Select CustomerID
From Customers
Where EXISTS
(Select CustomerID, Count(CustomerID) AS 'OrderCount'
From Orders
Group BY CustomerID
Having Count(Orders.CustomerID) < 5)
I need to somehow compare the list of names before I ask it to see which ones have ordered less than 5 times.
Thanks
If you want to use LEFT JOIN, interchange the table names since you want to show values from Customers, otherwise use RIGHT JOIN instead.
SELECT Customers.CustomerID,
COUNT(Orders.CustomerID) AS OrderCount
FROM Customers
LEFT JOIN Orders
ON Orders.CustomerID = Customers.CustomerID
GROUP BY Customers.CustomerID
HAVING COUNT(Orders.CustomerID) < 5
using EXISTS()
SELECT CustomerID
FROM Customers c
WHERE EXISTS
(
SELECT 1
FROM Orders o
WHERE o.CustomerID = c.CustomerID
GROUP BY CustomerID
HAVING COUNT(CustomerID) < 5
)
Try this:
SELECT C.CustomerID, C.CustomerName, COUNT(O.CustomerID) AS OrderCount
FROM Customers C
LEFT JOIN Orders O ON O.CustomerID = C.CustomerID
GROUP BY C.CustomerID
HAVING OrderCount < 5
ORDER BY OrderCount, C.CustomerName
I'm trying to find the revenue from customers in an country (United States).
The relevant tables are:
Order Details: Order ID, Unit price, quantity,
Orders: Order ID, customerID
Customers: customerID, country.
I'm not sure how to do this. I was thinking multiple inner join but it doesn't work.
The error message is "Syntax error (missing operator) in query expession 'ORDER DETAILS].ORDERID = ORDER.ORDERID
INNER JOIN CUSTOMERS ON CUSTOMERS.CUSTOMERID = ORDERS.CUSTOMERID'
MS online said Error 3075
Here is what I have:
SELECT SUM(QUANTITY*UNITPRICE) AS Result
FROM [ORDER DETAILS]
INNER JOIN ORDERS ON [ORDER DETAILS].ORDERID = ORDER.ORDERID
INNER JOIN CUSTOMERS ON CUSTOMERS.CUSTOMERID = ORDERS.CUSTOMERID
WHERE COUNTRY = 'Argentina'
Thanks in advance.
Edit: table structure
http://postimg.org/image/oojygytkv/
In Access if you are JOINing more than two tables together then it requires parenthesis. Try the following:
SELECT SUM(QUANTITY * UNITPRICE) AS Result
FROM ([ORDER DETAILS]
INNER JOIN ORDERS ON [ORDER DETAILS].ORDERID = ORDERS.ORDERID)
INNER JOIN CUSTOMERS ON CUSTOMERS.CUSTOMERID = ORDERS.CUSTOMERID
WHERE COUNTRY = 'Argentina'
I currently have this query:
select
customers.emailaddress,
MAX(orders.orderdate) as "last order"
from orders
join customers
on orders.customerID = customers.customerID
group by customers.emailaddress
Which gives me the emails, and the last order date. With the 'Orders' table, there is a field named 'PaymentTotal', how can I get this based on the value returned by MAX(orders.orderdate)? (ie am trying to get the amount of the last order per email)
select c.EmailAddress, om.MaxOrderDate, o.PaymentTotal
from (
select CustomerID, MAX(orders.orderdate) as MaxOrderDate
from orders
group by CustomerID
) om
inner join orders o on om.CustomerID = o.CustomerID
and om.MaxOrderDate = o.orderdate
inner join customers c on o.customerID = c.customerID