Also, you should consider migrations to be the first-class citizen and entities to be derived on it. On our system, we have

migration "create-users-table" { create-table "users" { column "id" "number" dbtype="increments" } }

migration "add-user-last-device" { alter-table "users" { column "last_device" "string" } }

This implicitly defines an "User" entity which has two fields, "id" and "lastDevice". But now we can also generate migrations (in our case, knex migrations). It’s harder and less reliable to go the other way, starting from current database schema + current description to migration.