identity column causes grief when populating table - suggestions?

[Trevor Squires]

Hi,
I've been googling all morning and can't find info to solve this problem 
(using derby of course), I hope someone here can help...

As I write my application I have a script which blats and recreates my 
database and then populates the tables with test data.

However, many of my tables have identity columns and it's causing the 
following error when I insert the data:

 11:06:26  [INSERT - 0 row(s), 0.016 secs]  [Error Code: 30000, SQL 
State: 42Z23]  Attempt to modify an identity column 'ID'.

Here's my table:
create table sample (
        id int not null generated always as identity,
        description varchar(128) not null,
        quantity double not null,
        constraint product_pk primary key (id)
);
Here's my insert statement
insert into sample (ID, DESCRIPTION, QUANTITY) values (1, 'blah', 1.1);
I've tried to create the table without "generated always as identity" 
and then altering the table after the insert(s).

Unfortunately I can't get the syntax right and I can't figure out if 
there's a way to turn off identity generation temporarily.

Does anyone have any suggestions like pointer to the right way to do 
this or a relatively painless workaround?

Thanks for listening,
Trevor