Re: ALTER TABLE modifications

Rod Taylor writes:

> ALTER TABLE tab ADD COLUMN col DEFAULT 3, ADD CHECK (anothercol > 3);
> The above combinational syntax is commented out in gram.y. The
> support framework is used in both the above and below items, but
> arbitrary statements probably have some issues -- I've not
> tested enough to determine.
>
> If it is useful, it will be submitted at a later date.

I think it's perfectly fine to write two separate ALTER TABLE statements.
No need to introduce this nonstandard syntax.

> ALTER TABLE tab ALTER COLUMN col TYPE text TRANSFORM ...;
> Currently migrates indexes, check constraints, defaults, and the
> column definition to the new type with optional transform. If
> the tranform is not supplied, a standard assignment cast is
> attempted.

Please don't use the term "transform". It is used by the SQL standard for
other purposes. What kind of object would you put in place of the "..."
anyway? A function? What syntax do other databases use?

--
Peter Eisentraut peter_e(at)gmx(dot)net