Re: some basic oracle questions (assertions etc)

spliffmonkey_at_iname.com wrote:
> I have a couple of questions. If you dont know the answer could you
> point me somewhere that has info on this type of basic stuff:
>
> 1. I want to creat an assertion that states that IF A is 'yes' then B
> and C are NOT NULL. (whereas if A is 'no' then null is acceptable for B
> and C)
>
> 2. If a table of, say, buildings requires a builder, I would specify
> that
> builder would be NOT NULL.
> However, if a table of buildings could have several builders (1 or
> more)
> then I would have a separate table where they both together formed a
> primary key.
> Now my question: How do you specify that a building MUST have a
> builder?
> i.e. how do you ensure that there is an entry for a particular building
> in
> the building-builder table?
>
> 3. Whats wrong with this join?:
> select * from Ride, Rideservicemen where Rideservicemen.Ridename =
> Ride.Ridename;
>
> When it joins the two tables, Ridename is printed twice each time?
>
> Thanks

Is there some reason why you feel posting the same question three times will do more than irritate people?

1. Do your own homework
2. Do your own homework
3. This is not valid syntax ... you need to identify and correct your error. To do this carefully reread the statement and validate your syntax. -- Daniel A. Morgan http://www.psoug.org damorgan_at_x.washington.edu (replace x with u to respond)