[Zope] Z PyGresql DA questions

[Paul Chung Chee Soong]

Hi. I'm building a loan system with Zap and I have a SQl statement   
problem. Let's say I have 2 table:  loan and  doc

Fields in doc:    pno *
                   doctype *
  docloc
  ...

Fields in loan: usrid *
      pno *
  doctype *
  ...
Note: * means primary key

What I want to query is how do I get all the pno and its according type,   
that doesn't exist in the loan table? This is to make sure that the   
borrower does not select a document that had been loaned!!! In other   
words, all documents except those that are being borrowed.

Please reply to hcsccs@prudential.com.my as well.

Many thanks,
Paul Chung
Paul Chung
Executive
IT Department
Prudential Assurance Malaysia Berhad