How can I delete all the row that matchs a specific filter ?
Something like
DELETE /items?filter={"where":{"color":"blue"}}
You could refer to the loopback documentation to delete persisted model and filter
In your NODE code
Books.destroyAll({"or":[{"id":1},{"id":2}]}, callback)
In your REST API
http://localhost:3000/api/Books?filter={"where":{"or":[{"id":1},{"id":2}]}}
If you update your question with the code that is not working for you, I could update the answer to address your problem.