[SQLObject] Issue with expiring objects.

[Peter W. <pw-...@te...>]

Hi,
I've been looking to use expiring objects from the cache and have been 
running into situations where they don't see to be getting expired 
correctly.

I've put together a simple test case that in my understand should work 
for each of the 3 versions but fails to re-select from the db unless 
extra prints are put in and a reset of the variable.

If any one could run the script below and either confirm that it is 
failing and should be working or my understanding is incorrect I'd be 
very appreciative.

--
Regards,
Peter Wilkinson.


#!/usr/bin/env python2.3

from SQLObject import *

conn = MySQLConnection(user='USER', db='DB', passwd='PASS')

class Contact(SQLObject):
     _table = 'test_contact'
     _connection = conn
     firstname = StringCol()
     lastname = StringCol()

#
# version 1 - doesn't work, only selects from the db twice
#
print "----- 1 -----"

Contact.createTable()
Contact.new(firstname = 'First', lastname = 'Last')

a = Contact(1) # first read
b = Contact(1) # cached
print "a: (First) ", a.firstname
print "b: (First) ", b.firstname

conn.query("update test_contact set firstname = 'Change' where id = 1")

b.expire()
a = Contact(1) # read again

print "a: (Change) ", a.firstname # gets correct value

conn.query("update test_contact set firstname = 'Another' where id = 1")

b.expire()
b = Contact(1) # should read again
print "a: (Another) ", a.firstname # this is not correct
print "b: (Another) ", b.firstname # this is not correct

Contact.dropTable()

#
# version 2. sort of works a is out of whack at the end
#
print "----- 2 -----"

Contact.createTable()
Contact.new(firstname = 'First', lastname = 'Last')

a = Contact(1) # first read
b = Contact(1) # cached
print "a: (First) ", a.firstname
print "b: (First) ", b.firstname

conn.query("update test_contact set firstname = 'Change' where id = 1")

b.expire()
a = Contact(1) # read again

print "a: (Change) ", a.firstname # gets correct value
print "b: (Change) ", b.firstname # FIX - this makes b up-to-date after 
the next expire

conn.query("update test_contact set firstname = 'Another' where id = 1")

b.expire()
b = Contact(1) # should read again, making a up-to-date
print "a: (Another) ", a.firstname # this is not correct
print "b: (Another) ", b.firstname # gets correct value

Contact.dropTable()

#
# version 3. works
#
print "----- 3 -----"

Contact.createTable()
Contact.new(firstname = 'First', lastname = 'Last')

a = Contact(1) # first read
b = Contact(1) # cached
print "a: (First) ", a.firstname
print "b: (First) ", b.firstname

conn.query("update test_contact set firstname = 'Change' where id = 1")

b.expire()
a = Contact(1) # read again

print "a: (Change) ", a.firstname # gets correct value
print "b: (Change) ", b.firstname # gets correct value

conn.query("update test_contact set firstname = 'Another' where id = 1")

b.expire()
b = Contact(1) # should read again, making a up-to-date
a = Contact(1) # FIX - this makes a up-to-date
print "a: (Another) ", a.firstname # gets correct value
print "b: (Another) ", b.firstname # gets correct value

Contact.dropTable()