Re: O'Reilly interview with Date

Kenneth Downs wrote:
>
> Joins can then be specified between two tables by specifying the
> distinguishing features of the foreign key, and you can even leave out this
> step if doing so will unambiguously pick the right one.
>
> So this:
>
> SELECT child.* from parent join child

Is this necessarily a semijoin?

> would be valid if there existed only one foreign between them. If there
> existed a myriad of keys and we chose to name the keys, we might do this:
>
> SELECT child.* from parent join child key KEYNAME

Okay, but this doesn't address the namespace unification issues that I raised previously.

Marshall Received on Wed Aug 10 2005 - 22:27:53 CEST