Insert Select to move between buckets

SQL++
1

I am in need to move a large amount of docs between two buckets on the same server. Based on the sample found

INSERT INTO `travel-sample` (KEY UUID(), VALUE _country)
    SELECT _country FROM `travel-sample` _country
      WHERE type = "airport" AND airportname = "Heathrow"
RETURNING *;

i was wondering if there is a way to copy the whole doc without specifying all the fields to copy /insert into the new doc and also use some values from the old doc like _type and _id to construct a new key which is same as the old one. Or is there a way to get the meta().id to use the same key as the original id. If i take all fields from the source doc, how can i add like a field of _type=‘message’ ? to the doc being saved ?
Finally is there a way to delete the source doc automatically after the new doc has been created ?

2 
INSERT INTO `travel-sample` (KEY id, VALUE  doc)
    SELECT  META(t).id AS id, OBJECT_ADD(t,"_type", "message") AS  doc FROM `travel-sample` t
      WHERE t.type = "airport" AND t.airportname = "Heathrow";

If you want different key you can construct it either in select projection or INSERT
example: (KEY “message::”||id , VALUE doc ) …

If u planning to use UUID() if repeat command there might be duplicates because each time it gets different key.
You can also use UPSERT …

If large amount of data you can choose other options.

  1. backup and restore with different bucket name
  2. USE SDKs get and update different bucket
  3. may be other options
3

What would the syntax be if i want to add 2 objects like _type and _id.
There wont be a duplicate key issue as its a one time import into a different bucket

4 
OBJECT_ADD(OBJECT_ADD(t,"_type", "message") , "_id", "xyz")
OR
OBJECT_CONCAT(t, {"_type:"message","_id":"xyz")