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Using Python for business app development

Heikki Tuuri Heikki.Tuuri at innodb.com
Fri Dec 27 09:09:03 EST 2002 
Karl,

"Karl A. Krueger" <kkrueger at example.edu> wrote in message
news:augajk$6ps$1 at baldur.whoi.edu...
> Heikki Tuuri <Heikki.Tuuri at innodb.com> wrote:
> > "David Rushby" <woodsplitter at rocketmail.com> wrote in message
...
> 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
...

yes, the constraint is actually enforced for InnoDB type tables in MySQL
http://www.innodb.com/ibman.html#InnoDB_foreign_keys.

> 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.

For MyISAM type tables MySQL simply ignores the FOREIGN KEY syntax, and does
not check at runtime that the constraint is satisfied.

> 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.

InnoDB is included in both the stable MySQL-Max-3.23 branch and in the
development branch MySQL-4.0. You can download them from
http://www.mysql.com. In MySQL you can concurrently use different table
types, of which the main are MyISAM, HEAP, InnoDB, and BDB.

> [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

Best regards,

Heikki Tuuri
Innobase Oy
---
InnoDB - transactions, row level locking, and foreign key support for MySQL
See http://www.innodb.com, download MySQL-Max from http://www.mysql.com
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