[ZDP] BackTalk to Document The Zope Book (2.5 Edition)/Relational Database Connectivity
Thu, 22 Aug 2002 04:55:04 -0400
A comment to the paragraph below was recently added via http://www.zope.org/Documentation/Books/ZopeBook/current/RelationalDatabases.stx#2-2
Database Connections are used to establish and manage connections
to external relational databases. Database Connections must be
established before database methods can be defined. Moreover,
every Z SQL Method must be associated with a database connection.
Database adapters (or DAs for short) are available for a number of
Oracle -- Oracle is a powerful and popular commercial relational
database. This DA is written and commercially supported by Zope
Corporation. Oracle can be purchased or evaluated from the "Oracle
Sybase -- Sybase is another popular commercial relational database.
The Sybase DA is written and commercially supported by Zope
Corporation. Sybase can be purchased or evaluated from the "Sybase
ODBC -- ODBC is a cross-platform, industry standard database protocol
supported by many commercial and open source databases. The ODBC DA
is written and commercially supported by Zope Corporation.
PostgreSQL -- PostgreSQL is a leading open source relational
database. There are several database adapters for PostgreSQL
including "ZPoPy":http://sourceforge.net/projects/zpopyda/ which
is maintained by Zope community member Thierry Michel. You can
find more information about PostgreSQL at the "PostgreSQL web
MySQL -- MySQL is a fast open source relational database. You
can find more information about MySQL at the "MySQL web
The MySQL DA is maintained by Zope community member Monty Taylor.
Interbase -- Interbase is an open source relational database
from Borland/Inprise. You can find more information about
Interbase at the "Borland web
site":http://www.borland.com/interbase/. You may also be
"FireBird":http://sourceforge.net/projects/firebird which is a
community maintained offshoot of Interbase. The Zope Interbase
adapter is maintained by Zope community member Bob
Gadfly -- Gadfly is a relational database written in Python by
Aaron Waters. Gadfly is included with Zope for demonstration
purposes and small data sets. Gadfly is fast, but is not
intended for large amounts of information since it reads the
entire database into memory. You can find out more about Gadfly
at the "Chordate website":http://www.chordate.com/gadfly.html.
% Anonymous User - May 30, 2002 4:03 pm:
Whoa! "Database Adaptors" come out of left field, with no description of what they are and how they fit into
the scheme of "Database Connectors" and "Z SQL Methods", both of which have been described and related to
% Anonymous User - June 26, 2002 2:33 pm:
I have figured this out; you only need a Connection object for the specific database, for example zope
includes Z Gadfly Connection, you can install the MySql Connection and you will use the same Z Sql Methods as
always, the connector will do the job of translating the zope languaje to the database interface... is this
% Anonymous User - June 26, 2002 4:33 pm:
This is right. Although you aren't *limited* to one, you can have several different database connections for
each kind of database. For example, you can have two MySQL connections in the same Zope, each of which point
to a different MySQL database.
% Anonymous User - Aug. 22, 2002 4:55 am:
I was wondering whether each user is handled in a different session. So if 2 users connect to a site (not
cached) that uses batching. Will each user be handled separately or could there be a conflict?
The same applies to the connection: Is each user using the same connection? Does Zope handle the sharing of
this single connection?
The same applies to the ZSQL as well of course.