ALTER TABLE contact ADD COLUMN identifier1 varchar(1024);
ALTER TABLE contact ADD COLUMN identifier2 varchar(1024);
ALTER TABLE contact ADD COLUMN identifier3 integer;
UPDATE contact SET identifier1 = '' WHERE identifier1 IS NULL;
UPDATE contact SET identifier2 = '' WHERE identifier2 IS NULL;
UPDATE contact SET identifier3 = '0' WHERE identifier3 IS NULL;
ALTER TABLE contact ALTER COLUMN identifier1 SET DEFAULT '';
ALTER TABLE contact ALTER COLUMN identifier2 SET DEFAULT '';
ALTER TABLE contact ALTER COLUMN identifier3 SET DEFAULT '0';
ALTER TABLE contact ALTER COLUMN identifier1 SET NOT NULL;
ALTER TABLE contact ALTER COLUMN identifier2 SET NOT NULL;
ALTER TABLE contact ALTER COLUMN identifier3 SET NOT NULL;
