Question

I am trying to run a query to return the customer first and last name only if the IP address they have used for a session is different.

for example:

Customer 1 makes Order on Session IP address: 192.168.12.1
Customer 1 makes Order on Session IP address: 192.168.12.2

Customer 2 makes Order on Session IP address: 192.168.12.3
Customer 2 makes Order on Session IP address: 192.168.12.3

Return Customer where IP address is not same (Customer 1)

However, I can’t work out how to specify the difference in the IP address.

What I currently have is:

Select Cust_First, Cust_Last
FROM customer

LEFT join Session
On customer.cust_ID = session.Cust_ID

LEFT join Order
On session.Ses_ID = order.Session_ID

Where Ses_IPAddress # Is different for the same customer? 

I’ll detail the tables with the necessary fields:

Customer:
PK: Cust_ID
row: Cust_First
row: Cust_Last

Session:
PK: Ses_ID
FK: Cust_ID
Row: Ses_IPAddress

Order:
PK: Order_ID
FK Ses_ID

Answer 1

Actually the task is way easier than the way you are trying to complete it. Just select these customers from the ones that do fit your logic.

SELECT Cust_First, Cust_Last
FROM Customer
WHERE Cust_ID IN (
    SELECT Cust_ID
    FROM Session
    JOIN Order On Session.Ses_ID = Order.Ses_ID
    GROUP BY Cust_ID, Session.Ses_IPAddress 
    HAVING COUNT(1) > 1
)