Function MongoCollection.distinct

Returns an input range of all unique values for a certain field for records matching the given query.


							
					auto distinct(R, Q)
					(
					

					  string fieldName,
					

					  Q query,
					

					  DistinctOptions options = DistinctOptions.init
					

					);

Parameters

Name	Description
fieldName	Name of the field for which to collect unique values
query	The query used to select records
options	Options to apply

Returns

An input range with items of type R (Bson by default) is returned.

Example

import std.algorithm : equal;
import vibe.db.mongo.mongo;

void test()
{
	auto db = connectMongoDB("127.0.0.1").getDatabase("test");
	auto coll = db["collection"];

	coll.drop();
	coll.insertOne(["a": "first", "b": "foo"]);
	coll.insertOne(["a": "first", "b": "bar"]);
	coll.insertOne(["a": "first", "b": "bar"]);
	coll.insertOne(["a": "second", "b": "baz"]);
	coll.insertOne(["a": "second", "b": "bam"]);

	auto result = coll.distinct!string("b", ["a": "first"]);

	assert(result.equal(["foo", "bar"]));
}

Authors	Sönke Ludwig
Copyright	© 2012-2016 Sönke Ludwig
License	Subject to the terms of the MIT license, as written in the included LICENSE.txt file.