On Tue, 2002-06-25 at 01:08, [EMAIL PROTECTED] wrote: > Your message cannot be posted because it appears to be either spam or > simply off topic to our filter. To bypass the filter you must include > one of the following words in your message: > > sql,query > > If you just reply to this message, and include the entire text of it in the > reply, your reply will go through. However, you should > first review the text of the message to make sure it has something to do > with MySQL. Just typing the word MySQL once will be sufficient, for example. > > You have written the following: > > On Mon, 2002-06-24 at 17:50, Roger Baklund wrote: > > * [EMAIL PROTECTED] > > [...] > > > The referred to keys are the same type and are indexed (they are > > [...] > > > CREATE TABLE genres ( > > > genre_id SMALLINT NOT NULL PRIMARY KEY, > > [...] > > > genre_id SMALLINT, > > > > ...does not look the same to me... ;) > > Ouch, you are correct, although they are the same *type*. However, this > seems like a fairly severe restriction. Obviously a primary key must be > NOT NULL, but there are certainly cases where a column which refers to a > foreign key must be NULL. The docs do say that the foreign key > constraints *can* have an ON DELETE SET NULL clause, which is > meaningless if your column has to be set to NOT NULL due to referring to > a primary key. > > Perhaps this is only a deficiency, and not a bug, but the documentation > could be a bit clearer on this. It says, "Corresponding columns in the > foreign key and the referenced key must have similar internal data types > inside InnoDB so that they can be compared without a type conversion." > My understanding is that NOT NULL is only a column constraint and > doesn't affect the data type. > > However... Even when I set the referring column to be SMALLINT NOT NULL, > and create a new database, I still get the same error: > > ERROR 1005 at line 23: Can't create table './MP3d/tracks.frm' (errno: > 150) > > -- > Andy Dustman PGP: 0x930B8AB6 > @ .net http://dustman.net/andy > "Cogito, ergo sum." -- Rene Descartes > "I yam what I yam and that's all what I yam." -- Popeye > -- Andy Dustman PGP: 0x930B8AB6 @ .net http://dustman.net/andy "Cogito, ergo sum." -- Rene Descartes "I yam what I yam and that's all what I yam." -- Popeye
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