I would like to transfer a model and its data from
stage-1. Preferably I would like existing data to be updated and new data to be created. It would also be good if IDs are not reassigned so I don’t lose references. How would I go about this?
We offer migrations to transfer models between environments, you can see the full documentation here: Primary and sandbox environments - DatoCMS
We also offer auto-generation of migration scripts: Environments and migrations - Write and test migration scripts - DatoCMS Docs
That works for model and field differences, but doesn’t work at the moment for content (records). For the records the only option is to manually write migration scripts.