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:
- 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)
- 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?
- 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
Received on Thu Dec 08 2005 - 15:49:24 CST