Mongo equivalent of `select distinct(name) from employee where age = “25”`

Question

I need help with finding distinct values but I also need to give a filter condition.
I have managed the distinct in this fashion :

$unique = $db->command(array("distinct" => "employee", "key" => "name"));  

How do I add the "where age = "25" " clause to this?

Thanks for you help!

Answer 1

distinct() in the MongoDB shell, and the distinct command both take a query argument which is used to filter the set of records to consider when determining distinct key values. In your example, you could do:

db.employee.distinct("name", {"age": 25})

in the MongoDB shell, or:

$db->command(array("distinct" => "employee",
                   "key" => "name",
                   "query" => array("age" => 25)))

in PHP.