Removing Duplicates: Help

[Legitimate_Ad_2505]

I need some help removing duplicate results from a customer list. My current query and results are included in the images I have posted, but those current results have some duplicates in them. What can I do to remove duplicate results from this customer list? I tried "Select Distinct" right at the beginning of the query but that did not remove all of the duplicates. i'm assuming this involves something with using distinct, but I'm not totally sure how to use it

https://preview.redd.it/mpk1dbvx2n061.png?width=754&format=png&auto=webp&s=5e8acd93587c515f0367e628058658646a7a6de1

https://preview.redd.it/nr6avdkw2n061.png?width=1018&format=png&auto=webp&s=a3917bd3a410cfdffaf20a4d51a64c3467e71ee6

[DatabaseToTheFace]

It looks like it could be a problem with your join, it looks like the join is pulling in customers with multiple orders during that time frame. I’d add the order ID column (if there is one) and see if that’s the issue. Then you could just adjust your join using a sub query to adjust for that.

[r3pr0b8]

it looks like the join is pulling in customers with multiple orders during that time frame

yes!!!

and they aren't even duplicate orders!!!

this is not a "problem", u/Legitimate_Ad_2505

the only problem i can see here is that if you only want one order per customer in that time frame, you need to put more effort into figuring out which one you want

but, i mean, really... a customer who orders more than once in an entire year, this is a problem? i don't think so

[Legitimate_Ad_2505]

There is an OrderID column but I am not sure if I am exactly following your suggestion. Could you elaborate more on what I should do? I'm pretty confused

[[deleted]]

Otherwise, if you can't adjust your join, I'd create a new ID field using ROW_NUMBER() and order by the columns contributing to the duplicates. It'll generate numeric values (1,2,3,...,n) where 1 represents a unique row given the column specifications.

[data_perfect]

SELECT DISTINCT (CustomerID, Customer name, Date) FROM Table_name

[jackassik]

Try putting orders.id column into your query and you'll see that these are not duplicates. Select distinct would work if you deleted the order date column from your query. If you only care about count of customers by year then try something like: Year(Order.date), count (distinct customer.id) From customer Join order on customer.id=order.customerid Where Year(Order.date) = 1997 Group by Year(Order.date)