CouchDB-Python retrieving documents

Question

The following document is a small example and is stored in CouchDB.

{
  "_id": "Test4",
  "referenceName": "refA",
  "positions": {
      "A": 422,
      "B": 5442
  },
  "details": {
      ...
      "infoA": "AQQ811P0",
      ...
  },
  ...
}

Now I am not quite sure how write a function def retrieve_infoA(name="AQQ811P0") to only retrieve:

• id
• referenceName
• positions

Answer 1

Have you created a CouchDB view to retrieve the data? It will look something like this:

{
  "_id": "_design/ddoc",
  "views": {
    "by_infoA": {
      "map": "function(doc) {
                   if(doc.details && doc.details.infoA)  {
                      emit(doc.details.infoA);
                   }
              }"
    }
  },
  "language": "javascript"
}

You can then call the view with a URL fragment similar to this:

/dbname/_design/ddoc/_view/by_infoA?key="AQQ811P0"

You will retrieve the whole document, but in your application you only use the fields that you are interested in.

See here for more information.