Using DA v19.1.1 I did a model compare against a live database. Differences were correctly identified. However, when the merge script was generated, there were several errors in the script. Because columns were entered in the middle of tables, the tables were renamed, created with the new columns in correct order, and then existing data was inserted into the new table using a select from the previously renamed table. The table included an IDENTITY column, so SET IDENTITY_INSERT tablename ON/OFF was needed. DA failed to include the table name as part of the statement, simply writing in the script SET IDENTITY_INSERT ON followed by SET IDENTITY_INSERT OFF. Obviously, this would not work without the table name.
Also, DA failed to Drop or rename all necessary FK constraints, resulting in another problem when the script was run.
Using V16 of DA, I was able to create a correct Merge script.
Anyone else experience a similar problem? Looks like the Compare/Merge functionality took several steps back.
Update -- V19.2 seems to fix the problem with the IDENTITY_INSERT, however, at least one FK was missed as needing to be dropped and re-created .