PHP mysql Order by and Group By query

Question

In my order history, I am currently listing all the customers previous orders, however, not in date order. My current query is :

SELECT OrderItemID, Date
FROM orderitems
WHERE OrderID=$orderid
GROUP BY OrderID;

After this query, I use a while loop, for each order found, to print the past order in a table. However I want to print past orders by 'ORDER BY Date'. After the GROUPBY I put ORDER BY Date Desc, but had no difference in results printing.

Any guidance would be appreciated.

Answer 1

Since you are filtering the records with OrderID , why do you need to GROUP BY it?

SELECT OrderItemID, Date
FROM orderitems
WHERE OrderID=$orderid
ORDER BY Date DESC

Answer 2

I'm not sure why OrderItems would have the date of the order. Based on the text, I suspect you want something like this:

SELECT OrderID, Date
FROM Orders o
WHERE CustomerId = $CustomerId
ORDER BY Date DESC;