You can use the Unload/load commend to implement the migration, i.e. first unload the database from 3.x, and then load it to the 4.x. following is the steps, take 3.7 and 4.2 databases for example:

1. Backup the old database if necessary.
2. In the dmSQL of DBMaker3.7 connected to the original database (we named it MIS), unload MIS database to a target directory, say C:\ 37MIS \.
3. Copy all the Files in DB_FoDir into the directory C:\ 37MIS \.
4. Create a new database; we named it NEWMIS, with DBMaker 4.2 with the same section configuration as MIS in dmconfig.ini but the different database directory.
5. In the dmSQL of DBMaker4.2 connected to the NEWMIS database, load the old database from the target directory, say C:\ 37MIS \.
6. End of migration job.
7. Check if all the objects, including stored procedure, UDF, View still work in the new database and enjoy the new function of DBMaker 4.2.

Also, the migration database job needs patience and there are more notices, for the details about the database migration, please refer to the DBMaker Migration User’s Guide manual.