jean/products.sqlalchemyda

SQLAlchemyDA is a generic database adapter for ZSQL methods. Since it is based on SQLAlchemy, SQLAlchemyDA supports all databases out-of-the box that are supported by SQLAlchemy (Postgres, MySQL, Oracle, SQLite, MS-SQL, Firebird, Informix).

Zope ZSQL-SQLAlchemy Integration Wrapper

About SQLAlchemyDA

SQLAlchemyDA is a generic database adapter for Zope ZSQL methods, which are an older/legacy SQL templating feature for executing relational database queries from with in a Zope to transaction context.

SQLAlchemyDA provides an implementation in the form of a Zope2 "product" which wraps z3c.sqlalchemy, so that database connections are installable as objects in the Zope2 ZMI. Such connection objects can be set up to connect to any kind of database backend supported by SQLAlchemy using a database URI, such as Postgres, MySQL, Oracle, SQLite, MS-SQL, Firebird, Informix. However, some of these database backends have not been tested with the SQLAlchemyDA, so your mileage may vary.

In addition to ZSQL support, the SQLAlchemyDA makes it possible to use the standard SQLAlchemy API within a Zope2 context and participate in Zope transactions.

However, if you do not require ZSQL support, and only wish to call 'normal' SQLAlchemy APIs within Zope transactions, this package adds no value. Instead, you would be better off trying out zope.sqlalchemy, as recommended in the Zope2 book chapter on relational database connectivity.

Requirements:

• Zope 2.10+
• SQLAlchemy >= 0.5.0 (+ database specific low-level Python drivers)
• z3c.sqlalchemy >= 1.2.0

Installation:

• download and install SQLAlchemy as egg or from the sources from Cheeseshop (easy_install sqlalchemy). See

  http://www.sqlalchemy.org

  for details

• download and install z3c.sqlalchemy as egg or from the sources from Cheeseshop (easy_install z3c.sqlalchemy). See

  http://cheeseshop.python.org/pypi/z3c.sqlalchemy/

  for details.

• unpack the archive containing SQLAlchemyDA inside the "Products" directory of your Zope instance home.

• after restarting Zope you go to the ZMI and create an instance of "SQLAlchemyDA" (as you would create some DA instance)

• click on the new created SQLAlchemyDA instance within the ZMI and configure your database connection through the "Properties" tab. The connection parameter 'dsn' must be specified as a valid SQLAlchemy DSN like

  <dbschema>://<username>:<password>@<hostname>/<databasename>

  Example:

  postgres://admin:123@localhost:5432/TestDB

• ZSQL methods should see the new DA through the selection widget of available database adapters

• NOTE: you must have the low-level Python DB drivers installed in order to access a particular database. See

  http://www.sqlalchemy.org/docs/dbengine.html#dbengine_supported

  for details.

Configuration of SQLAlchemyDA:

• 'dsn' - SQLAlchemy compliant Database Set Name (see www.sqlalchemy.org/docs)

• 'transactional' - uncheck this property if you are working with a non-transactional

  database like older versions of MySQL. Uncheck this property only if you see any commit() related error. Otherwise leave this property checked. Changing this property requires a Zope restart.

• 'quoting_style' - affects how strings are quoted in SQL. By default 'standard'

  quotes strings correctly. Setting the value to 'no-quote' might solve quoting issues with some databases.

Using SQLAlchemyDA:

SQLAlchemyDA works as a database adapter as documented within "The Zope Book"

http://www.plope.com/Books/2_7Edition/RelationalDatabases.stx

and can be used like any other DA together with ZSQL methods.

Tested with databases:

• Postgres 7.4, 8.0-8.2
• SQLite 3.3.X
• Oracle 10g
• MySQL is only supported for MySQL databases with transaction support. (see also z3c/sqlalchemy/README.txt)

Known issues:

""" Database connection could not be opened ((ProgrammingError) (1064, You have an error in your SQL syntax near 'COMMIT . """

This bug might appear with older MySQL versions when opening/closing the connections manually through the ZMI. It should not affect the functionality of SQLAlchemyDA.

Author

SQLAlchemyDA was written by Andreas Jung for Haufe Mediengruppe, Freiburg, Germany and ZOPYX Ltd. & Co. KG, Tuebingen, Germany.

License

SQLAlchemyDA is licensed under the Zope Public License 2.1. See LICENSE.txt.

Contact

Sheila Allen

E-mail: sallen at zeomega.com

Credits

Parts of the SQLAlchemyDA V 0.3.X development has been sponsored by Wayne Volkmuth (renovis.com).

More recent SQLAlchemy support and maintenance sponsored by ZeOmega.com.