Please refer to the Neutron documentation Script Auto-generation for the instruction to auto-generate migration scripts.
You need to specify –subproject networking-midonet option to the neutron-db-manage command to generate a migration script for this project.
Depending on *aaS and other sub-projects set up in your environment, you might need to edit the generated script. Typically, you need to remove extra “drop table” ops for tables which don’t belong to our project.