Looking Up Data from a Query based on Combobox selection

[Charlieboy]

Hi



I am busy tryong to learn how to use access and am creating a simple Database based on invoice for a garden service. I am no where complete and am trying to understand ways of doing things.

I currently have created a query that subtotals the lines per invoice, I have then created a form to process to the payment table, I have a combo box selecting the customer ID and the Invoice ID, I am trying to get a text box to populate the total from the subtotal query for that spoecific Invoice ID and have tried everything with no luck

can anybody please assist.

Charlie

[June7]

A basic principle of relational database is 'enter raw data, do calcs in reports'. It is poor design to save 'running sum' (aggregate) calculated data and is a path of endless frustration. Why would you save an invoice amount to payment table? Payment table should record customer payment (amount, payment type, reference such as check no./cash/credit card).

[Charlieboy]

I am not trying to Save the invoice value to the table, I merely wanted it as a view on the form so that when posting a payment one would see what the actual value of the Inovice was, I wanted it more for reference than an actual post to the payment table.

I am learning as I go, and trying to build according to what I would like to see.

[June7]

You did say 'process to the payment table' so that gave me to believe you wanted to save calculated value. If all you want to do is display the total on a form, that can be tricky. Forms are really intended as a data entry interface, not to report back summary info 'on-the-fly'. I don't know enough about your project structure to be specific. Do you want to provide it for analysis?

[Charlieboy]

I will Attache a copy of my DB, its a real mess, as I am using it to learn and mess about in before I attempt to create a final, so it might seem overcomplicated

Cheers