This makes code simpler, faster and easier to understand.
It is easy to forget that ZODB connections can be reused by different threads,
which led to bug such as the one fixed by commit 2c11b76a.

ZODB already maintains a pool of connections to reuse
so we don't need anymore to have one.

When a ZODB connection is closed, it usually returns to a ZODB pool and may be
reused by another thread. If the SQL connection was open and is still in ZODB
cache, the _v_database_connection attribute is still there:
ActivityConnection.connect() is not called and a new instance of ZMySQLDA.db.DB
is created for the new thread without initializing its sort key.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@37270 20353a03-c40f-0410-a6d1-a30d3c3de9de

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@37268 20353a03-c40f-0410-a6d1-a30d3c3de9de

If a query string has a semicolon at the end, remove it. Otherwise, MySQLdb simply generates a programming error.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@37264 20353a03-c40f-0410-a6d1-a30d3c3de9de

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@37263 20353a03-c40f-0410-a6d1-a30d3c3de9de

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@37153 20353a03-c40f-0410-a6d1-a30d3c3de9de

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@34689 20353a03-c40f-0410-a6d1-a30d3c3de9de

Fix error position computation: MySQL limits the length of the output SQL chunk, requiring more tricks to find offset error correctly.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@25473 20353a03-c40f-0410-a6d1-a30d3c3de9de

Replace default MySQL error text (for sql syntax error) with more complete - though as uggly - error.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@25472 20353a03-c40f-0410-a6d1-a30d3c3de9de

Remove MySQL dependency from CMFActivity. Translate a lock error into ConflictError in database adapters instead.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@20317 20353a03-c40f-0410-a6d1-a30d3c3de9de

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@17868 20353a03-c40f-0410-a6d1-a30d3c3de9de

WARNING: this is an upstream-incompatible feature. If upstream allows access to compression in another way and you enable this feature, you will have to update your connection string yourself.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@16312 20353a03-c40f-0410-a6d1-a30d3c3de9de

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@15203 20353a03-c40f-0410-a6d1-a30d3c3de9de

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@15152 20353a03-c40f-0410-a6d1-a30d3c3de9de

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@15150 20353a03-c40f-0410-a6d1-a30d3c3de9de

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@13937 20353a03-c40f-0410-a6d1-a30d3c3de9de

Add a missing word in docstring.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@13847 20353a03-c40f-0410-a6d1-a30d3c3de9de

Fix big thread concurency mistake in ZMySQLDA/db.py: the object registerable to transaction manager was the one chared by all threads, preventing multiple threads from effectively registering to transaction manager. This caused MySQL deadlocks, since commits were never issued in all concurent threads but one. This patch creates a new intermediate object between DB and DA which just handles pooling - and factorising connection string parsing and server capabilities probing.
Update DA so it uses the intermediate class.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@13846 20353a03-c40f-0410-a6d1-a30d3c3de9de

Use the new method everywhere instead of directly calling database's query method.
Add a "ping" query at request begining to offer transactionnal use a reconnection opportunity.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@13704 20353a03-c40f-0410-a6d1-a30d3c3de9de

Make getConnection, cleanupConnections, getFinishedOrAborted, setFinishedOrAborted, forceReconnection, closeConnection private methods.
Remove useless try block in _finish.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@13697 20353a03-c40f-0410-a6d1-a30d3c3de9de

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@13672 20353a03-c40f-0410-a6d1-a30d3c3de9de

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@13671 20353a03-c40f-0410-a6d1-a30d3c3de9de

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@13670 20353a03-c40f-0410-a6d1-a30d3c3de9de

Remove volatile-attribute-related code, it has nothing to do on such class.
Rename the flag used to know wether _abort or _finish has to be called.
Initialise that flag during _begin.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@13666 20353a03-c40f-0410-a6d1-a30d3c3de9de

Remove transaction and query locks. Since DB instances are stored in a volatile attributes on ZMySQLDA instances, they are bound to one thread at most, so it's not needed to handle concurent accesses, and removing them should induce a performance increase.
Remove a tabulation caracter.
Delete volatile attribute at transaction end (_finish and _abort) to avoid multiple threads from using the same connection - because of ZODB connection pooling.


git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@13629 20353a03-c40f-0410-a6d1-a30d3c3de9de

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@13627 20353a03-c40f-0410-a6d1-a30d3c3de9de