Re: Nearest Common Ancestor Report (XDb1's $1000 Challenge)

> > change 'john' to 'johnny' ... cant because of constraints...
>
> I had forgotten to include DRI actions when I posted the
> script for my implementation. Everywhere I wrote "references things", I
> should have written "references things on update cascade on delete
> cascade". I'm perfectly willing to supply the code for the trigger
> if necessary to convince you.

No need to supply the code. I accept that the proper DRI would change 'john' to 'johnny' in all remaining tables that used 'john' and I accept that the chance of future programmers forgetting to add the necessary DRIs for new related tables is very low.

> >Using data itself to link redundant data is a non-generic solution.
>
> Huh? Please elaborate.

Suppose your things table allows two things to have the same name, ie 'john' and 'john' (to approximate the genericness of the db created with XDb1). In things table, each 'john' is a different record (and hopefully there are enough other attributes to distinguish them; if not, an id column might be added).

Now suppose you have a 2nd table called hierarchies and wish to link its parent column with rows from things table. In this case, the data (ie 'john') could not be used to perform the link, because it would be ambigious. Thus, using data itself to link redundant data is a non-generic solution. Received on Sat May 22 2004 - 20:48:57 CEST