I have a table T (PBM_CLAIM BIGINT, CLAIM_SRC SMALLINT, ...) with the unique constraint:
ALTER TABLE RELAY_CLAIM ADD CONSTRAINT U_RELAY_CLAIM_SRC UNIQUE (PBM_CLAIM,CLAIM_SRC); If I try to insert a row with (NULL, NULL, ...) when this constraint exists, I get the error ISC ERROR CODE:335544334 ISC ERROR MESSAGE: conversion error from string " " I drop the constraint, and the insert works. I'm at a loss to understand what's going on, as adding the constraint to an existing table works and there are thousands of rows where the tuple is (NULL,NULL). A simple test table with only a few test rows, these two columns, and the unique constraint works fine. Does anyone have any ideas or experience anything like this?