java - Map Reduce Couch Db -

i have simple database couch db. have users have fields:

string username string password string mail boolean admin 

i keep users @ db. new couch db , nosql. how can implement map reduce on example (or internally , don't need anything?)

i use spring 3 , ekorp application.

in couch, add field in documents called

_type

or

type_

the map function be

function(doc) {  if(doc.type_=="user") {     emit(doc.name,doc._id);  } }