Thanks for your answer
I messed up the code snippet; forgot the commit.
Please check updated attachment.
AFAIU, what is going on there is:
-- the code opens the first connection (without a transaction);
-- a new table is created via connection 1;
-- a new row is inserted via connection 1;
-- the code opens another connection, and BEGINs a transaction ;
-- the code draws two copies of the row via connection1 and connection2;
-- the code changes the attribute .foo of the FIRST copy;
-- the code prints the attribute .foo of the SECOND copy that was drawn via
another transaction, and the value is still 'init' because it isn't
changed - the code hasn't changed trans_dummy.foo yet.
I intended to illustrate following behavior:
Two instances of the same class with same id; one pulled via a
connection (with cache=False); one pulled via a transaction createt from
that same connection;
--> Commits to the transaction _do_ invalidate the instance pulled via
connection (thanks to cache=False);
--> Changes to the connection instance _don't_ invalidate the
transaction instance;
This asymmetric behavior seems strange to me, since (as far as i
understood the code), the transaction object even uses the same cache;
it's using the same DBConnection instance, after all.
I use SQLObject for a GUI app, so I need long living instances;
transactionally separated.
Can I evade manually syncing all the transactions. If not, what's the
best way to invalidate a transaction's cache for a given instance/all
instances of given class. Are there any docs on this?
regards Herwig Hochleitner
import sqlobject
# Turn off caching so that multiple connections (ie transactions) sync properly
conn = sqlobject.connectionForURI("sqlite:/:memory:", debug=True, logger="database.query", loglevel="debug", cache=False)
class Dummy(sqlobject.SQLObject):
foo = sqlobject.StringCol()
Dummy.createTable(connection=conn)
Dummy(foo="init", connection=conn)
tr = conn.transaction()
conn_dummy=Dummy.get(1,conn)
trans_dummy=Dummy.get(1,tr)
print "Writing 'connection_val' to connection foo"
conn_dummy.foo = "connection_val"
print "Value of transaction foo: '%s'" % trans_dummy.foo
print "Writing 'transaction_val' to transaction foo"
trans_dummy.foo = "transaction_val"
tr.commit()
print "Value of connection foo: '%s'" % conn_dummy.foo
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