Guidance on updating an ORD database from a (much) earlier version

[bdeadman]

Is your feature request related to a problem? Please describe.
If an organisation has been using a very early version of the ORD to store their internal data, there may be challenges in updating the ord-schema to later versions.

Describe the solution you'd like
Some documentation to outline the process. Where version changes are found to change the ORM and how it functions, or deprecate certain fields or ENUMs then advice can be provided on how to migrate old data through the change.

[bdeadman]

0.3.37 -> 0.3.38 ord_schema.orm.mappers overhauled to use programmatic ORM definitions instead of explicitly defined classes. After this change it is no longer possible to use:

from ord_schema.orm.mappers import Compound, CompoundIdentifier, Reaction, ReactionInput

[skearnes]

You need to change your imports to use the Mappers object: https://github.com/open-reaction-database/ord-schema/blob/main/ord_schema/orm/rdkit_mappers_test.py#L29

[bdeadman]

0.3.37 -> 0.3.38 NAME ReactionIdentifierType ENUM changed to REACTION_TYPE.