mongodb - Query Collection for Subsets -

trying query mongo collection documents subsets of object (query). e.g.

object: {      "animal": "cat"     ,"owner": "mike"     ,"color": "blue"     ,"city": "houston" }  collection: [     [0]{          "color": "red"         ,"animal": "cat"     }     [1]{          "color": "blue"     }     [2]{          "owner": "mike"         ,"city": "houston"     } ]  result:     [1]{         "color": "blue"     }     [2]{          "owner": "mike"         ,"city": "houston"     } 

you need build query dynamically based on properties of javascript object.

the query like:

$and : [     {$or : [{ color: { $exists: true, $eq: 'blue' } }, {color: { $exists:false} }]},     {$or : [{ owner: { $exists: true, $eq: 'mike' } }, {owner: { $exists:false} }]},     ...     // iterate through other properties. ] 

edit:

using $and means documents in collection have property must match object - change $or match of attributes.

edit 2

also worth considering performance poor large collections if don't use indexed attributes in query. 1 solution problem use array , multikey index.

i.e.

{ tags : [ "color=blue","owner=mike" ] } 

this way can use regex \^color=\ return docs class= tag , use index. \^color=blue\ blues.

then multiple conditions use $all or $in operators.

e.g.

{ tags : { $in: [/^color=blue/, /^owner=mike/]} } 

hope helps