Using Access 2000.

I want to programmatically add a field to a table and
modify another field. Can I write an ALTER TABLE
statement, or do I have to change it via tabledef?

Also, one of the fields we change from text to numeric,
which invalidates some data (which is okay). Right now, I
open the table in design mode, change the field, save the
table. Access warns of the error and I just accept it.

Will I be able to change the field in SQL (or via
tabledef), or will these invalid values cause Access to
not allow me to do that?