SQL Developer

Hi,

I compared 2 schemas with the "Schema diff" tool. In the result i found a lot of very strange results:

ALTER TABLE A
ADD ("ID" NUMBER NOT NULL)
;

ALTER TABLE A
DROP COLUMN "ID"
;

I did not run the resulting SQL-file. The differences should still be in the schemas. If i compare these columns manually, with selecting the data from the dictionary (dba_tab_columns, dba_constraints, dba_cons_columns, etc.) i can't see any differences.

Is this a problem of the tool or where can i find this differences?

Tom

P.S. The tool creates the same output for constraints (Primary Keys, Foreign Keys, Unique).