I'd like to map the following structure: - I have blog posts - Blog posts can have comments - Comments can have replies (which are also comments), so it should be a recursive datastructure
POST -----*--> COMMENT
COMMENT -----*---> COMMENT
Here's what I tried:
mappings: { "comment": { "properties": { "content": { "type": "string" }, "replies": { "type": "comment" } } }, "post": { "properties": { "comments": { "type": "comment" } } } } Of course it's not working. How can I achieve this?
You're trying to declare the types as you would do in OO programming, that's not how it works in ES. You need to use parent-child relationships like below, i.e. post doesn't have a field called comments but the comment mapping type has a _parent meta field referencing the post parent type.
Also in order to model replies I suggest to simply have another field called in_reply_to which would contain the id of the comment that the reply relates to. Much easier that way!
PUT blogs { "mappings": { "post": { "properties": { "title": { "type": "string"} } }, "comment": { "_parent": { "type": "post" }, "properties": { "id": { "type": "long" } "content": { "type": "string" }, "in_reply_to": { "type": "long" } } } } } 
in_reply_to field joins the replies to the comments. Thanks! mappings: { "post": { "properties": { "content": { "type": "string" }, "comment": { "properties" : { "content": { "type": "string" }, "replies": { "properties" : { "content": { "type": "string" } } } } } } 
"The parent and child types must be different — parent-child relationships cannot be established between documents of the same type."