[Zope] ZSQL Methods and transaction control

[Tino Wildenhain]

robert rottermann schrieb:
> Hi there,
> 
> I am implementing a tool to handle userdata that is stored in a MySQL db.
> The underlaying logic of the stored procedures used to maintain the db
> content
> dictate that I have to control the transactions myself.

Can you elaborate on that? I dont see a reason why you would
commit around zopes transaction handling (which would actually
be dangerous anyway - think of the retry mechanism in case of
database conflicts)

> I understand that there is a way to handle transaction controll in the
> ZMySQL
> methods. However I find no documentation at all on how to use it.

Well most databases accept "COMMIT" as sql command.

> Without using ZMySQL methods I would be using the following piece of code:
> db = mysql.connect(host="localhost" ...)
> cursor = db.cursor()
> query = "CALL insertUser('%s', '$xxx$', @id, @error);select @id, @error"
> % 'JohnTheUser'
> cursor.execute(query)
> # get the next resultset, it has the result of the select
> cursor.nextset()
> result = cursor.fetchall()[0]
> error = int(result[1])
> if error:
>     print "error %s when trying to add user %s" % (ERRRORS[error],
> 'JohnTheUser')
>     db.rollback()
>     continue #we are in a loop actually

what does the loop?
> ..
> db.commit()
> How can I mimic that using ZSQL Methods

Are you adding users in a series? What exactly
are you doing? If its kind of migation, consider
running it as a script with zopectl run migationscript.py
once. There you could just write python code as you like
w/o interfering w/ Zopes session handling.

Regards
Tino