Hello,
I have another borderline question about SQL in SQLite. Look at the
following example
---
PRAGMA foreign_keys = ON;
CREATE TABLE toto1 ( id_toto1 INTEGER PRIMARY KEY
, id_toto2_and_toto3 INTEGER NOT NULL
,
Is this legal to have a foreign key that references several tables?
Why not? I'd say it's a very bad database design (or extremely rare
and questionable reason to do that) but there's nothing wrong in it
from SQL point of view.
Pavel
On Wed, Oct 13, 2010 at 6:55 AM, TP
Pavel Ivanov wrote:
Is this legal to have a foreign key that references several tables?
Why not? I'd say it's a very bad database design (or extremely rare
and questionable reason to do that) but there's nothing wrong in it
from SQL point of view.
Thanks Pavel.
I'm rather new at SQL. I
On Wed, 13 Oct 2010 12:55:40 +0200, TP
paratribulati...@free.fr wrote:
Is this legal to have a foreign key
that references several tables?
It is legal, but it is uncommon or even very rare.
Why? Well, a foreign key column (id_toto2_and_toto3)
identifies a row (tuple) in the referred table
Kees Nuyt wrote:
That is to say, any value in id_toto2_and_toto3 has a
corresponding row in both toto2 and toto3.
You have to ask yourself if toto2 and toto3 shouldn't be
combined into one table.
As far as I can tell, the only reason to not combine them
would be some performance
