Select * group by in mongo aggregation

Question

I am trying to do something that I think is quite simple. Suppose I have a series of records in mongo that have a common key, and variable number of attributes. I want to select

Answer 1

Here is the another way of doing it :

$connection = 'mongodb://localhost:27017';
$con        = new Mongo($connection); // mongo connection

$db         = $con->test; /// database
$collection = $db->prb; // table

$keys       = array("Name" => 1,"x"=>1,"y"=>1,"z"=>1);

// set intial values
$initial    = array("count" => 0);

// JavaScript function to perform
$reduce     = "function (obj, prev) { prev.count++; }";

$g          = $collection->group($keys, $initial, $reduce);

echo "
";
print_r($g);


You will get the answer something like this (not the exact output) :

Array
(
    [retval] => Array
        (
            [0] => Array
                (
                    [Name] => George
                    [x] => 
                    [y] =>
                    [z] =>
                    [count] => 2
                )

            [1] => Array
                (
                    [Name] => Rob
                    [x] => 
                    [y] =>
                    [z] =>
                    [count] => 1
                )

        )

    [count] => 5
    [keys] => 3
    [ok] => 1
)