Why do I get Unknown column 'block_device_mapping.uuid after upgrading OSP12 to 13 upgrade ?

Issue

• The instances are up and running, but commands like ‘openstack server show ’ are failing. The same for Horizon, it doesn’t show server details.

• nova-api is showing the following errors:

2019-02-12 16:04:18.359 22 ERROR oslo_db.sqlalchemy.exc_filters   File "/usr/lib/python2.7/site-packages/pymysql/connections.py", line 1340, in read
2019-02-12 16:04:18.359 22 ERROR oslo_db.sqlalchemy.exc_filters     first_packet = self.connection._read_packet()
2019-02-12 16:04:18.359 22 ERROR oslo_db.sqlalchemy.exc_filters   File "/usr/lib/python2.7/site-packages/pymysql/connections.py", line 1014, in _read_packet
2019-02-12 16:04:18.359 22 ERROR oslo_db.sqlalchemy.exc_filters     packet.check_error()
2019-02-12 16:04:18.359 22 ERROR oslo_db.sqlalchemy.exc_filters   File "/usr/lib/python2.7/site-packages/pymysql/connections.py", line 393, in check_error
2019-02-12 16:04:18.359 22 ERROR oslo_db.sqlalchemy.exc_filters     err.raise_mysql_exception(self._data)
2019-02-12 16:04:18.359 22 ERROR oslo_db.sqlalchemy.exc_filters   File "/usr/lib/python2.7/site-packages/pymysql/err.py", line 107, in raise_mysql_exception
2019-02-12 16:04:18.359 22 ERROR oslo_db.sqlalchemy.exc_filters     raise errorclass(errno, errval)
2019-02-12 16:04:18.359 22 ERROR oslo_db.sqlalchemy.exc_filters InternalError: (1054, u"Unknown column 'block_device_mapping.uuid' in 'field list'")
2019-02-12 16:04:18.359 22 ERROR oslo_db.sqlalchemy.exc_filters