Multiple key search in CouchDB

Question

Given the following object structure:

{
   key1: "...",
   key2: "...",
   data: "..."
}

Is there any way to get this object from a CouchDB by quering both key1 and key2 without setting up two different views (one for each key) like:

select * from ... where key1=123 or key2=123

Kind regards, Artjom

edit:

Here is a better description of the problem: The object described above is a serialized game state. A game has exactly one creator user (key1) and his opponent (key2). For a given user I would like to get all games where he is involved (both as creator and opponent).

Answer 1

Emit both keys (or only one if equal):

function(doc) {
  if (doc.hasOwnProperty('key1')) {
    emit(doc.key1, 1);
  }
  if (doc.hasOwnProperty('key2') && doc.key1 !== doc.key2) {
    emit(doc.key2, 1);
  }
}

Query with (properly url-encoded):

?include_docs=true&key=123

or with multiple values:

?include_docs=true&keys=[123,567,...]

UPDATE: updated to query multiple values with a single query.

Answer 2

You could create a CouchDB view which produces output such as:

["key1", 111],
["key1", 123],
["key2", 111],
["key2", 123],
etc.

It is very simple to write a map view in javascript:

function(doc) {
    emit(["key1", doc["key1"]], null);
    emit(["key2", doc["key2"]], null);
}

When querying, you can query using multiple keys:

{"keys": [["key1", 123], ["key2", 123]]}

You can send that JSON as the data in a POST to the view. Or preferably use an API for your programming language. The results of this query will be each row in the view that matches either key. So, every document which matches on both key1 and key2 will return two rows in the view results.

Answer 3

I also was struggling with simular question, how to use

"select * from ... where key1=123 or key2=123". 

The following view would allow you to lookup customer documents by the LastName or FirstName fields:

function(doc) {
  if (doc.Type == "customer") {
      emit(doc.LastName, {FirstName: doc.FirstName, Address: doc.Address});
      emit(doc.FirstName, {LastName: doc.LastName, Address: doc.Address});
  }
}