Why don't you just use ZSQL Methods?!


Seth Gottlieb wrote:
The problem seemed to be that Zope.app() was returning a new root object instance every time a new DAO (data access object) was initialized. After 3, boom.

The work around is to pass the context of the calling object with syntax like __of__(self) when you call methods of the DAO. You can also pass in a reference to the calling object in the method call dao = getDAO(self,....). Then the method on the DAO you can use

setattr(self, CONNECTION_NAME, getattr(context,CONNECTION_NAME))

Where CONNECTION_NAME is a string with the same name as the Z SQL Connection object that the calling object acquired.

Seth Gottlieb wrote:

Thanks Michele,

I was thinking of doing that as well. Did you point the DA to SQLRelay? Or did you have your Python code connect directly to SQLRelay? My application needs to be able to roll back transactions when told to by the transaction manager. Do you know if going around Zope's DB Connectivity would cause a


Michele Marcionelli ([EMAIL PROTECTED]) wrote:

Hash: SHA1

Hello Seth,

I ran exactly in the same problem and I installed SQL Relay
(http://sqlrelay.sourceforge.net/) that manage better (i.e. good) the
connections than ZMySQLDA. If someone has a solution to the problem...


On 25.10.2005, at 23:12, Seth Gottlieb wrote:


I have a Python class that my Zope application uses to talk to a
relational database (MySQL for now).  I am using a Z SQL Connection
(ZMySQLDA) object to handle DB connectivity.  When I initialize, I get
a handle of the connection object like this:

import Zope
setattr(self, CONNECTION_NAME, getattr(Zope.app(),CONNECTION_NAME))

Where CONNECTION_NAME is a string that matches the ID of the
    connection object that I have in the Root folder of Zope.

Then I run queries like this:

from Products.ZSQLMethods.SQL import SQL

setattr(self, '_selectProperties',
           SQL('_selectProperties', '', CONNECTION_NAME, 'schemaId',
           'SELECT * FROM ' + TABLE_NAME[self._context.id] + ' WHERE
                 SCHEMA_ID = <dtml-sqlvar schemaId type="int">'))

The life of this class should be Zope transaction (I am hooking into
Shared.DC.ZRDB.TM.TM to manage these objects).

The problem I am running into is I seem to be running out of
connections.   Everytime I inititialize and run "show processlist;"
within MySQL, the number of connections increases.  I get to a maximum
of 3 and then my Zope instance hangs.

Is there any reason why these DB connections do not get reused or
destroyed after queries are made?

Any ideas?



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