Question

I’m working with an accounting system with a Visual Foxpro backend. Every month, all of the invoices and payments are moved from the current invoices/payments table to a new table (in a different directory) with just that month’s data. For example:

MainDBDir
    currentInvoices.dbf   (contains Dec invoices)
    currentPayments.dbf  (contains Dec payments)
    2010Dir
        NovDir
            invoices.dbf (contains Nov2010 invoices)
            payments.dbf (contains Nov2010 payments)
        OctDir
            invoices.dbf (contains Oct2010 invoices)
            payments.dbf (contains Oct2010 payments)

I need to execute a queries on the last six months of data. Is there a way I can concatenate multiple tables (from multiple directories) in a single Visual Foxpro query?

I need something like this:

 select * from concatenate(currentInvoices, 2010Dir/NovDir/invoices.dbf, 2010Dir/OctDir/invoices) where invoice_number like '12345'

I’d rather not execute a separate query for each table…

Thanks-

Jonathan

Answer 1

You can concatenate the queries by using a union statement.

Example:

select * from currentInfoices.dbf
  where invoice_number like '12345'
union
select * from "2010Dir\OctDir\invoices.dbf"
  where invoice_number like '12345'
union
select * from "2010Dir\NovDir\invoices.dbf"
    where invoice_number like '12345'

or

select * 
  from (select * from currentInfoices.dbf
          union select * from "2010Dir\OctDir\invoices.dbf"
     union select * from "2010Dir\NovDir\invoices.dbf") q
  where invoice_number like '12345'