Hi! ----- Original Message ----- From: ""Martijn Tonies"" <[EMAIL PROTECTED]> Newsgroups: mailing.database.myodbc Sent: Wednesday, December 03, 2003 4:46 PM Subject: Re: on delete|update
> Hi, > > > Hi there. I am trying to find what these > > ON DELETE NO ACTION > > > > ON UPDATE NO ACTION > > > > would provide ib my db..... What are the options and what each of them do? > > These have to do with Foreign Key Constraints. If you're using > InnoDB tables, you could let MySQL automatically drop any > child objects by using ON DELETE CASCADE. > > NO ACTION will raise an exception if there are child objects > and you're trying to delete/update a parent row. I have to correct that ON DELETE NO ACTION means that no foreign key check is done at all if there is a DELETE in the parent table. The default behavior is RESTRICT, which performs the check. > With regards, > > Martijn Tonies > Database Workbench - developer tool for InterBase, Firebird, MySQL & MS SQL > Server. > Upscene Productions > http://www.upscene.com Best regards, Heikki Tuuri Innobase Oy http://www.innodb.com Foreign keys, transactions, and row level locking for MySQL InnoDB Hot Backup - hot backup tool for InnoDB which also backs up MyISAM tables Order MySQL technical support from https://order.mysql.com/ -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
