How do I use a variable as a field name in a Mongo query in Meteor?
javascript, meteor, mongodb
Solution
The query is just a JavaScript object, so you can build it step by step:
var query = { _id: Session.get('parent_id') };
var myCustomField = Session.get('child_collection_name').decapitalise();
var myCustomValue = params.child;
query[myCustomField] = myCustomValue;
var count = SomeCollection.find(query).count();
Does that do the trick?
Problem
How would I go about using a variable as a field name in a Mongo query in a Meteor application. Here is an example... This runs a find on my request controllers collection after capitalizing the collection name for the parent id of a child. The child is the users field. ``` window[Meteor.request.controller.capitalise()]["find"]({ _id: Session.get('parent_id'), users: params.child }).count() ``` As you can see my controller is a variable name for the collection item which allows me to have a single line of code for finding children of controller/collections but I need to be able to set the child field name to a variable. In the above example that would be users but I want it to be a variable name. I have tried this but it does not work. ``` window[Meteor.request.controller.capitalise()]["find"]({ _id: Session.get('parent_id'), [Session.get('child_collection_name').decapitalise()]: params.child }).count() ``` where ``` Session.get('child_collection_name').decapitalise() ``` returns users Any ideas? If I can figure out how to use a variable name in a mongo query in meteor it would reduce my code footprint significantly.