TweetThere are a number of quarky little MongoDB commands and queries hidden in the docs, two of them are $size and $type. Does it really matter? $size that is … The $size operator matches any array with the specified number of elements. The basic use would be something like … > db.ideas.find( { votes : { $size: 2 } [...]

TweetSince MongoDB will allow you to store more than just string and int values but also things like arrays … from time to time you might need to know how many items are in an array in your document. For example, say you have a hosting business and to make a good profit you need [...]

TweetOne query SQL users are pretty used to writing is DISTINCT with COUNT() to get the number if distinct (unique) rows that match a statement like … SELECT COUNT(DISTINCT(PageURL)) FROM LogTable; This rather simple query will get us back the number of unique PageURL’s in our LogTable … not an amazingly useful query but you get [...]

TweetSay you have a log of hits to your podcast, something like … { “_id” : ObjectId(“4c6c753800ae261d80000009″), “podcastID” : 1, “remoteUserIP” : “10.40.52.55″, “remoteUserSession” : “gpn1vz1crveoqtgtlbh1tgd1″, “remoteUserAgent” : “iTunes/9.2.1 (Macintosh; Intel Mac OS X 10.6.4) AppleWebKit/533.17.8″, “created” : { “date” : “8/18/2010″, “time” : “5:05:12 PM” } } To get a quick snapshot of hits [...]