Question

This is the code that i used

UPDATE Customers c   
SET c.TotalP= 
   (SELECT SUM(b.Price) 
    FROM Products b
   WHERE b.CustomerID= c.CustomerID)

I im trying to set a value x to the TotalP field in the Customers table.
The value x is equal to the sum of the coressponding prices in the Products table where the Customer ID’s are the same.

The above code returns an error of "Operation must be an Updateable query"

Answer 1

You can use DSum:

UPDATE Customers   
SET TotalP = DSum("Price","Products","CustomerID = " & CustomerID)

But it does raise the question as to why you are updating a table with a calculated value when the information can be obtained from a query.