How to display the total of an order in a form

[yltang]

In an order system, there are tables of customers, products, orders, and order details, with the main fields listed as follows:

tblCostomer: CustomerID, CustomerName, ...
tblProduct: ProductID, ProductName, ...
tblOrder: OrderID, CustomerID, OrderDate, ...
tblOrderDetail: OrderID, ProductID, UnitPrice, Amount, Total, ...

I have created a query "qryTotalByOrder" which will sum up the total for each order by grouping corresponding products in that order:

qryTotalByOrder: CustomerID, OrderID, OrderDate, Total

I would like to add an unbound text box in a form " which will display the Total of a particular order by entering the orderID as a parameter. What do I need to put in the Source of Data of the textbox? Thanks.

[Stewart Ross]

Hi. The domain lookup function DLookup will do this for you. Assuming the OrderID field is numeric, enter

=DLookup("[Totals]", "[QryTotalByOrder]", "[OrderID] = " & [YourOrderIDTextboxName])

If the order ID is a string, you will need single quotes on either side of its value:

=DLookup("[Totals]", "[QryTotalByOrder]", "[OrderID] = '" & [YourOrderIDTextboxName] & "'")

-Stewart