Mongo User Defined Functions and Map Reduce

Question

Is there a way in mongo to create user-defined Javascript functions. I have several Map/Reduce functions on the client side that i would like to use within other MR function

Answer 1

Use

db.system.js.save( { _id : "myDatabaseAverage" , value : function(){
  // ..do something 
} } );

That will store the JS function on the server and can be accessed by m/r from that point on.

For further examples see : mongo/jstests/core/mr_stored.js

Answer 2

As mentioned by @Remon van Vliet,

You will have to use,

db.system.js.save( { _id : "myDatabaseAverage" , 
                     value : function(){ // ..do something } 
                 } );

to save your function first,

and then you need to call,

db.loadServerScripts();

before you execute your function.