Hello. I'm trying to wrap a function call in a transaction, but when I
intentionally throw an exception in the middle of the function it
doesn't actually roll back the transaction. The debug output says
1/ROLLBACK, without any 1/COMMITs in there, but when I view the data in
the command-line mysql utility the changes have been made.
This is the code I'm using to connect to the mysql database and to wrap
the function call in a transaction. After that I've invluded the
testUpdate method I'm using, and after that the python conversation
that ensued. Does anyone see what I'm doing wrong?
--- sqlutil.py:
from sqlobject import *
def connect():
""" Connects SQLObject to the dev database on localhost.
"""
connectionString =
"mysql://[EMAIL PROTECTED]/mc_image_library_dev?debug=1"
connection = connectionForURI (connectionString)
sqlhub.processConnection = connection
def wrapInTransaction (func, *args, **kw):
""" Got this from the SQLObject mailing list.
Calls the given func with the given args and keyword assignments
within a db transaction. Rolls back if an exception is thrown,
otherwise commits.
"""
old_conn = sqlhub.getConnection()
conn = old_conn.transaction()
sqlhub.processConnection = conn
try:
try:
value = func(*args, **kw)
except:
conn.rollback()
raise
else:
conn.commit()
return value
finally:
sqlhub.processConnection = old_conn
------------------
----- test.py:
from ImageCategory import *
def testUpdate (newName, username, fail):
category = ImageCategory.get(1)
category.name = newName
category.updateLastChanged (username)
if fail:
raise Exception ('spam', 'eggs')
-----------------
------ The python conversation:
>>> import sqlutil
>>> sqlutil.connect()
>>> import test
>>> sqlutil.wrapInTransaction (test.testUpdate, 'Animals', 'jake', True)
1/QueryOne: SELECT last_changed_by, last_changed_date, name FROM
image_category WHERE id = 1
1/Query : UPDATE image_category SET name = 'Animals' WHERE id = 1
1/Query : UPDATE image_category SET last_changed_by = 'jake' WHERE
id = 1
1/Query : UPDATE image_category SET last_changed_date = '2005-11-29
00:36:22' WHERE id = 1
1/ROLLBACK:
Traceback (most recent call last):
File "<stdin>", line 1, in ?
File "sqlutil.py", line 22, in wrapInTransaction
value = func(*args, **kw)
File "test.py", line 8, in testUpdate
raise Exception ('spam', 'eggs')
Exception: ('spam', 'eggs')
------------
After all this, the mysql utility shows that the update did take
effect.
Any thoughts?
- Jake
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