where clauses in storage/arlo

Status: out of date as of 0913.2005 ; has doctests.

This was Rick's original concept, based on ideas from SQLObject. He and I later did a pair programming session and decoupled these completely from SQL. See storage.QueryBuilder for the actual code.

= QueryBuilder =

The QueryBuilder uses Python's magic variables to generate SQL WHERE statements from Python expressions:

{{{
>>> user = QueryBuilder('user')
>>> user
user
>>> user.name
user.name
>>> user.name == 'rick'
user.name = 'rick'
>>> (user.name == 'rick') & (user.lastname == 'olson')
(user.name = 'rick') AND (user.lastname = 'olson')
>>> user.name.startswith('r')
user.name LIKE 'r%'
>>> user.name.endswith('k')
user.name LIKE '%k'
>>> user.name.contains('ic')
user.name LIKE '%ic%'
>>> user.ID >= 5
user.ID >= '5'
}}}

[http://techno-weenie.com.mn.sabren.com/ex/querybuilder.py.txt download]

The idea is you pass this QueryBuilder object to a method expecting a WHERE clause for an SQL query.  Also, it should be possible to convert the python expressions to other statements as well.  See my attempt at a MockQueryBuilder.