[ZDP] BackTalk to Document The Zope Book (2.5 Edition)/Relational Database Connectivity

[nobody@nowhere.com]

A comment to the paragraph below was recently added via http://www.zope.org/Documentation/Books/ZopeBook/current/RelationalDatabases.stx#2-2

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    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
    databases:

      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
      Website":http://www.oracle.com/.

      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
      Website":http://www.sybase.com/.

      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
      site":http://www.postgresql.org/.

      MySQL -- MySQL is a fast open source relational database. You
      can find more information about MySQL at the "MySQL web
      site":http://www.mysql.com/. 
      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
      interested in
      "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
      Tierney.

      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
       each other.

      % 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
       right?

      % 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.
       -Mac-