Python Programming On Win32

Sam Rushing’s ODBC Module

There is a third Python module for working with ODBC that operates on different lines. Sam Rushing (http://www.nightmare.com) specializes in low-level work with Python and Windows and has produced a package named calldll that allows Python programs to dynamically load and call any function in a DLL. We discuss how this works in Chapter 22. It has allowed Sam to produce an ODBC module that wraps and exposes almost every function in Microsoft’s ODBC.DLL. To install this, you need to download the two files calldll.zip and dynwin.zip from his site. The latter contains a number of modules relating to ODBC. Naturally, one of these is called odbc.py, so you need to watch for name collisions. If you’ve been using the previous two modules, rename them out of the way before starting.

As with the other modules, calldll provides a safe, easy-to-use high-level interface for querying databases, but it bears no resemblance to the DBAPI. Here’s the high-level usage:

>>> import odbc >>> env = odbc.environment() >>> conn = env.connection() >>> conn.connect('accessdemo') >>> import pprint >>> pp = pprint.pprint >>> results = conn.query('SELECT * FROM Invoices') >>> pp(results[0]) #field information [('InvoiceID', 4, 10, 0, 1), ('ClientID', 12, 10, 0, 1), ('InvoiceDate', 11, 19, 0, 1), ('Consultant', 12, 50, 0, 1), ('PeriodEnding', 11, 19, 0, 1), ('Hours', 8, 15, 0, 1), ('HourlyRate', 2, 19, 4, 1), ('Expenses', 2, 19, 4, 1), ('ExpenseDetails', 12, 50, 0, 1), ('TaxRate', ...