Taking sum of “column” in MongoDB

Question

In MySQL, I would simply go \"SELECT sum(pts) FROM table\" to get the sum of the pts column on the table. However, I am converting this application to MongoDB and cannot fin

Answer 1

Another solution is to create a script in the database, that will sum the require data and return your result something like:

The Script

function sum() {
   var sum = 0;
   for (var query = db.collection.find({}, {type: 1, _id:0}); query.hasNext();) {
      sum += query.next();
   }
   return sum;
}

PHP

In php after setting the connection with the db, it will be something like:

$toexec = 'function(x, y) { return sum() }';
$response = $database->execute($toexec, array());

Look this tutorial to learn more about scripting in mongo with php.

http://pointbeing.net/weblog/2010/08/getting-started-with-stored-procedures-in-mongodb.html