PouchDB startkey endkey not returning docs

Question

I seem to have an issue in retrieving a selected few documents from a PouchDB using startkey and endkey. I need to get the documents back with key starting with "profile" (in this example profile41 & profile48).

When using the chrome PouchDB extension, this works fine when doing a query using startkey:"profile" and endkey:"profile\0ffff", but for some reason, this doesn't work when running my code (angular/ionic).

My code returns an empty doc list. When I set the startkey:"profile41" and endkey:"profile41" I do get the doc back, so I know it connects and can retrieve documents from the DB.

PS: First use of PouchDB, so I might have overlooked something simple here.

Some documents in my db

{
  "_id": "animaltypes",
  "_rev": "7-e413c314272a62a6a14ed293f5f934cf",
  "value": {
    "rev": "7-e413c314272a62a6a14ed293f5f934cf"
  },
  "key": "animaltypes"
}
{
  "_id": "profile41",
  "_rev": "3-f4065b825d304d79479e3576409ce744",
  "value": {
    "rev": "3-f4065b825d304d79479e3576409ce744"
  },
  "key": "profile41"
}
{
  "_id": "profile48",
  "_rev": "3-5e62a6e33f022a8ac30d46b80126dedd",
  "value": {
    "rev": "3-5e62a6e33f022a8ac30d46b80126dedd"
  },
  "key": "profile48"
}

My javascript that retrieves docs

this.getData = function(keystart,keyend){
    var deferred = $q.defer();
    localDB.allDocs({include_docs: true, 
                     descending: true, 
                     startkey:keystart, 
                     endkey:keyend}, function(err, doc) {
        if (err) {
            deferred.reject(err);
        } else {
            var rows = [];
            for (var x in doc.rows) {
                rows.push(doc.rows[x].doc.data);
            }
            deferred.resolve(rows);
        }
    });
    return deferred.promise;
};

This returns an empty array with the following params

startkey = "profile"
endkey = "profile\0ffff"

This returns the correct single doc when parameters are set to

startkey = "profile41"
endkey = "profile41"

Answer 1

If you want to use "descending:true" you have to change the order of startkey and endkey.

Indeed, if you don't use "descending:true" you B-Tree looks like that:

1-  animaltypes
2 - profile41
3 - profile48

• startkey="profile" will be between id 1 and id 2
• endkey="profile\0ffff" will be after id 3

In result you will have 2 records

If you use "descending=true" you B-Tree looks like that:

1-  profile48
2 - profile41
3 - animaltypes

• startkey="profile" will be between id 2 and id 3
• endkey="profile\0ffff" will be after id 2 and id 3

in result you will have 0 record.