Using Python for business app development

[Karl A. Krueger]

Heikki Tuuri <Heikki.Tuuri at innodb.com> wrote:
> "David Rushby" <woodsplitter at rocketmail.com> wrote in message
> news:OBGO9.21074$BP.3877 at fe01...
>> - foreign keys (available with InnoDB tables, but with metadata
>> limitations:
>> "In the near future we will extend the FOREIGN KEY implementation so that
>> the information will be saved in the table specification file and may be
>> retrieved by mysqldump and ODBC.")
> I have to correct that for InnoDB type tables in MySQL the foreign key
> constraint definition metadata is accessible through mysqldump, ODBC, and
> JDBC. It is stored inside the InnoDB tablespace.

Yes, but is the constraint actually enforced?  Contrary to what MySQL
representatives and documentation have said in the past, foreign keys
are not "mostly used for documentation purposes" and they do not "make
life very complicated", nor is their primary functionality associated
with the ON DELETE option [1].  Foreign keys are used to implement
declarative constraints upon the data which may be inserted into the
database, based on relationships between the tables.  This is what
Oracle, Sybase, PostgreSQL, etc. all use them for.

According to the MySQL crash-me.php comparison [2], the current release
versions of MySQL claim "syntax only" support for foreign keys, meaning
presumably that the syntax is accepted (it is not a syntax error to
specify a foreign key relationship) but that the constraint is not
actually checked when rows are inserted.

Is this information from MySQL.com inaccurate?  Does your information
refer only to a third-party add-on to MySQL, or perhaps to an unstable
development version (as opposed to a production release version)?
Please clarify the resolution of this apparent contradiction.

[1] http://www.dbdebunk.com/qu071401.htm
[2] http://www.mysql.com/information/crash-me.php, data for MySQL 3.2.39
    and 4.0.6g

-- 
Karl A. Krueger <kkrueger at example.edu>
Woods Hole Oceanographic Institution
Email address is spamtrapped.  s/example/whoi/
"Outlook not so good." -- Magic 8-Ball Software Reviews