> What is the command to change the
> column to NOT NULL ?

There isn't any.

> alter table TEST
> alter f3 type decimal(18,7) NOT null
>
> but still hit an error ..

Create a NOT NULL domain and modify the datatype to the domain
or let a GUI tool like Database Workbench figure it out for you.

Martijn Tonies
Database Workbench - tool for InterBase, Firebird, MySQL, Oracle & MS SQL
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