I am currently in the process of writing a report that displays as a simple spreadsheet.  The purpose of this report is to display invoices with a breakout of the taxable line items as well as breaking out the tax itself.  Based upon how the data is stored, I have been unable to derive a function to withdraw it in the appropriate form.  To illustrate, here are examples of the tables that I am working with

The “Customer” Table

The “invoice” Table

The “Invoice_Detail” Table

As an end result, I am trying to have the data display in this format:

The Total Taxable and the Total Tax fields are the ones that are presenting the problem.  The conditions that I am trying to account for are the following:

-         “Total Taxable” equals the sum of all taxable line items containing a tax flag field that equals “Y” and a Tax code that does not end in “00”

-         “Tax Total” line equals the sum of all line items where GL_Account is between 3000 and 3999.

Does anyone have any ideas on how to code for the “Total Taxable” and “Total Tax” fields?