How to Remove a Validation

I converted a database from Access to SQL Server.
the Default value for one field in the access database
was set to >0. Now the the database is SQL Server and I
do not know how to change the >0 setting for one
field in one of the tables. There is no default value in SQL
server for this field. There is no indexes for this field either. The
error I am getting in the program is "The Value Entered is Prohibited
by the Validation Rule set for field schMCHNBR." How do I change the
Validation Rule to allow nothing to be selected. I tried checking allow nulls
and this did not work either. Thanks for your help.

open the table in design view, click the column name. what does the default value field have in it?

The default value had a 0 in there to begin with and it
did not work so I took the 0 out and left nothing and it
still did not work.

In Enterprise Manager design view, right-click the grid of columns. You can inspect indices & constraints on the table & see what rule is causing your problem.

I checked the Constraints and there are none. There is
one index but this field is not one of them. I righ clicked and
selected Check Constraints. Nothing there. Is there anything else
I can check. Thanks for your help.

Are you using an administrative user aco****, like sa? If you are in a normal user account you may not be able to see all the structure.

Just guessing, I've never run across a phantom constraint like this.