MongoDB query with an 'or' condition

Just thought I'd update in-case anyone stumbles across this page in the future. As of 1.5.3, mongo now supports a real $or operator: http://www.mongodb.org/display/DOCS/Advanced+Queries#AdvancedQueries-%24or

Your query of "(expires >= Now()) OR (expires IS NULL)" can now be rendered as:

{$or: [{expires: {$gte: new Date()}}, {expires: null}]}

In case anyone finds it useful, www.querymongo.com does translation between SQL and MongoDB, including OR clauses. It can be really helpful for figuring out syntax when you know the SQL equivalent.

In the case of OR statements, it looks like this

SQL:

SELECT * FROM collection WHERE columnA = 3 OR columnB = 'string';

MongoDB:

db.collection.find({
    "$or": [{
        "columnA": 3
    }, {
        "columnB": "string"
    }]
});

MongoDB query with an 'or' condition

db.getCollection('movie').find({$or:[{"type":"smartreply"},{"category":"small_talk"}]})

MongoDB query with an 'or', 'and', condition combined.

db.getCollection('movie').find({"applicationId":"2b5958d9629026491c30b42f2d5256fa8",$or:[{"type":"smartreply"},{"category":"small_talk"}]})

Query objects in Mongo by default AND expressions together. Mongo currently does not include an OR operator for such queries, however there are ways to express such queries.

Use "in" or "where".

Its gonna be something like this:

db.mycollection.find( { $where : function() { 
return ( this.startTime < Now() && this.expireTime > Now() || this.expireTime == null ); } } );