On Fri, Oct 07, 2005 at 10:45:06AM -0400, Robert Treat wrote: > On Thursday 06 October 2005 17:31, Michael Fuhr wrote: > > > > Also, notice the "TYPE innodb" clause of the CREATE TABLE > > statement. The default table type in MySQL is MyISAM, which > > doesn't support foreign key contraints at all, but which will > > silently allow you to declare them. If you haven't changed the > > default table type, then you must remember to specify that you > > want an InnoDB table, or else your REFERENCES clauses are nothing > > but documentation. > > I'm working on porting mediawiki to postgresql and was really > puzzled by the following: > > CREATE TABLE trackbacks ( > tb_id INTEGER AUTO_INCREMENT PRIMARY KEY, > tb_page INTEGER REFERENCES page(page_id) ON DELETE CASCADE, > tb_title VARCHAR(255) NOT NULL, > tb_url VARCHAR(255) NOT NULL, > tb_ex TEXT, > tb_name VARCHAR(255), > INDEX (tb_page) > ); > > I couldn't figure out why they weren't specifying type = innodb for > the table, but then figured they must have declared it some place > else or something... but now I see that even that wouldn't work. > Makes you wonder if my$ql users realize this behavior or not.... As a rule, they don't expect the database to handle any data integrity. This is a quite reasonable (lack of) expectation from that product. The trouble starts to happen when they run across DBMSs that *can* do this. > I would have to guess not because otherwise why would you use this > type of syntax at all? Right in one. > (And people claim my$ql is eaiser to use? I still don't get that > one) I was confused, too. Then it dawned on me. When people say, "MySQL is easier to use," what they really mean is, "I started from nothing. I worked hard getting used to these quirks, and I'll be *damned* if I'll consider all that painful effort wasted and start over." It reminds me a lot of the kind of mental gymnastics that cause people not to call the law when they realize they've been taken in by a con artist. In both cases, the emotional investment in not being wrong on an important matter is too big. Cheers, D -- David Fetter david@xxxxxxxxxx http://fetter.org/ phone: +1 510 893 6100 mobile: +1 415 235 3778 Remember to vote! ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings
