Working with DB Compare
It is important to know that DB Compare considers Schema 1 to be correct, and it generates DDL to make Schema 2 look like Schema 1. Moreover, it uses the term “added” for objects found only in Schema 2, “removed” for objects only in Schema 1, and “changed” for changed objects. These are represented by the colors green, red and blue respectively.
Taking a look at the second tab, Update Script, we have the DDL to drop the existing table in Schema 2 and recreate it to look like the one in table 1 with the added column. The Update Script is marked “Experimental,” as further modifications are being planned.
to the next, it could be because the environments are not really identical. Then it may be time to give DB Compare a try.