Hi
Table PTST has PK based on 3 columns UOP_NO, STATE_NO, TEST_NO, all
integer.

Rows get inserted e.g. with UOP_NO = 1, STATE_NO = 0, TEST_NO = 1
plus other column data but initially not with test_no = 0, I need to
add a new row setting TEST_NO = 0 with the existing UOP_NO & STATE_NO

This query runs once ok & then bombs out because of violation of
primary key (which I understand)

INSERT INTO PTST(UOP_NO, STATE_NO, TEST_NO, ABS_NO)
SELECT DISTINCT UOP_NO, STATE_NO, 0, -2
FROM PTST

Is there any way it can be modified so that once a row has TEST_NO =0
that there is no insert for that PK combination.

Hope that makes sense.

Thanks for any help
Jack