Обсуждение: Alter Table problems

I am attempting to add a few attributes to an existing table that already
contains data.  The problem that I am having is that the new attributes
that I want to add need to be forgein key references to other tables.  I
can't figure out how to create the attribute with a reference to another
table.  I tried the following, but all it did was create the
attribute... no forgein key:

ALTER TABLE student ADD COLUMN major REFERENCES degree_major;

I was also wondering how I would DELETE an attribute from an existing
table... i.e. ALTER TABLE student DELETE COLUMN major;

Any help would be much appreciated.  Thanks.

-Scott

On Fri, 27 Apr 2001, Scott David Walter wrote:

> I am attempting to add a few attributes to an existing table that already
> contains data.  The problem that I am having is that the new attributes
> that I want to add need to be forgein key references to other tables.  I
> can't figure out how to create the attribute with a reference to another
> table.  I tried the following, but all it did was create the
> attribute... no forgein key:
> 
> ALTER TABLE student ADD COLUMN major REFERENCES degree_major;

You can add the foreign key with something like:
ALTER TABLE student ADD CONSTRAINT <name> FOREIGN KEY(major)REFERENCES degree_major;

There are lots of little issues with alter table right now that
are getting fixed as time goes on.  I expect that some version
of drop column will make it into 7.2, for example.