Finally, this worked for me. Note that this is applicable only for OSQA using the bitnami environment with postgresql database.
if you want to restore your database state to the original version, first connect to postgres database using admin credentials(use any client, I used Dbeaver)
database : postgres
username : postgres
password : **admin password** : this is the same password you gave while installing bitnami-osqa
Now, drop the bitnami-osqa
database and create it again(if you already have connections to bitnami_osqa, close them)
Drop-database bitnami_osqa;
Commit;
Create-database bitnami-osqa;
Commit;
Now open use_osqa.bat in your bitnami root folder and execute the following
cd apps\osqa
python manage.py syncdb --all --verbosity 2
[specify yes when it prompts to create super user and create some user]
python manage.py migrate forum --fake