Cloudant different document structure in the same db

Question

I am new in cloudant and I have two different document structure in the same db as below for example.

I want to know how to list all documents with specific structure? Another question how can i list all document of type document 2 and related to reference to a specific document of type document 1 using Java?

e.g.:

Document1

{
"_id" : "dec_1",
"name" : "value",
"type" : "Value"
}

Document 2 : which hold reference to Document 1

{
"_id" : "ship_1",
"decRef" : "dec_1",
"size" : "1.0"
}

Answer 1

The canonical way to achieve this in Cloudant/CouchDB is to use a discriminator field which specifies the document type, and then use a view. For example:

Document 1:

{
    "_id": "dec_1",
    "name": "value",
    "type": "Value",
    "doctype": "dec"
}

Document 2:

{
    "_id" : "ship_1",
    "decRef" : "dec_1",
    "size" : "1.0",
    "doctype": "ship"
}

Then create a view where the map looks something like:

function (doc) {
   if (doc && doc.doctype) {
      emit(doc.doctype, null);
   }
}

Now you can list all documents of a given type by hitting the view

curl "https://U:P@U.cloudant.com/DB/_design/DDOC/_view/VIEW?key=\"dec\""
{"total_rows":1,"offset":0,"rows":[ 
    {"id":"dec_1","key":"dec","value":null}
]}