Questions on using Visio to do dB design

[Titus]

Hello,

I'm trying to use Visio 2003 Enterprise Architect version to do a basic dB
table design. Can someone please help me out with the following questions:

1) how can I set a column to "auto-increment", with a seed value, and the
increment amount?

2) once I've drag and dropped an Entity from the stencil onto the design
surface and selected it, what is the difference between:

a) clicking on a column name, select Edit, select Check tab, and enter
the check constraints, versus

b) clicking on "Check" under Categories, select Add (actually I'm not
quite sure what to add here)

Thanks