Updating a Highly Nested Document in Couchbase

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I have a document that contains multiple levels of hierarchy. Something like this:

{
  "id": "520707438",
  "pageURIHash": "3988665684",
  "children": [],
  "parentId": null,
  "content": "Here is a parent comment"
}

The children array may have other child comments as JSON objects, and each of the child in turn may have other children. Thus, this forms a highly nested structure.

Now, suppose I want to add a child comment to a comment with ID as 123456745. I am assuming that I know the root-level comment (so that I can use the USE KEYS clause in my N1ql query). How do I extract the children array corresponding to the comment with that particular Id and append a new comment to it? I could use the sub-document API but it requires me to know the path, and in this case, I do not know it.

I did a bit of research and came up with this query: 

"UPDATE default d use keys \"" + comment.getRootCommentId()
           + "\" SET (??? How do I get the existing array and append to it) FOR p WITHIN d.children WHEN p.id = \"" + comment.getId() + "\" END";

Thanks a lot!!

n1ql couchbase nosql mysql database
1 Answers

This should do what you want:

update default d use keys "foo"
SET p.children = ARRAY_APPEND(p.children, {
  "id": "20202020",
  "pageURIHash": "99999",
  "children": [],
  "parentId": null,
  "content": "New Stuff"
}) FOR p WITHIN d.children WHEN p.id = "520707440" END
user_15430050
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