Question

I have the following json (simplified) objects in a couchdb storage:

[{
    "_id": "5ea7a53e670b432e0fe22a7bc10024db",
    "_rev": "1-ae70c8906f7aa6d73539a89f7ad960ee",
    "type": "job"
}, {
    "_id": "5ea7a53e670b432e0fe22a7bc10041d9",
    "_rev": "4-fa0ba68c35ca548b497a7309389f9087",
    "type": "scan",
    "job_id": "5ea7a53e670b432e0fe22a7bc10024db",
    "number": 1
}, {
    "_id": "5ea7a53e670b432e0fe22a7bc100520e",
    "_rev": "4-3e6b1a028786c265ecb7362e245d049e",
    "type": "scan",
    "job_id": "5ea7a53e670b432e0fe22a7bc10024db",
    "number": 2
}]

I want to make a post request with the keys [“5ea7a53e670b432e0fe22a7bc10024db”, 2] (the job id and a scan number). How can I make a map function for a view to filter out the job that has the given id and the measurement that matches the job_id and the number?

Thanks,
Radu

Answer 1

What is you expected output of the request? If you just want to get the scan, emit in map the key you want to search for:

function (doc) {
  if (type == "scan" && number) {
    emit([doc.job_id, doc. number], doc);
  }
}

If you need two documents — the job (full document, not just id) and the scan, either emit both of them in single emit with include_docs=true parameter in the request’s URL:

function (doc) {
  if (doc.type == "scan" && doc.number) {
    emit([doc.job_id, doc. number], {scan: doc, _id: doc.job_id});
  }
}

or in two emit‘s with:

function (doc) {
  if (doc.type == "scan" && doc.number && doc.job_id) {
    emit([doc.job_id, doc. number, "job"], {_id: doc.job_id);
    emit([doc.job_id, doc. number, "scan"], {_id: doc._id});
  }
}

You will get both document with startkey=["5ea7a53e670b432e0fe22a7bc10024db", 2]&endkey=["5ea7a53e670b432e0fe22a7bc10024db", 2, {}]&include_docs=true (or keys=[]) in the URL.

Check the view API for the include_docs option.