Help

I have a simple question:

If in a table definition, certian fields are defined not to be null.

How do I check whether there is such a constraint using sql?

For instance, suppose there is a table say

	create table A (a integer constraint aa primary key,
			b integer constraint bb not null);

Later I will write code to insert (4, -). In order to avoid exception in Java, and suppose I don't know constraint bb, I need to check the table A whether there is a constraint for b. How can I do that?

Thx in advance.

Haoyu Received on Fri Aug 02 2002 - 23:41:22 CDT