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0.8.1

Asynchronous I/O that doesn’t get in your way, written in D

Function MongoCollection.distinct

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

auto auto distinct(R, Q) (
  string key,
  Q query
);

Parameters

NameDescription
key Name of the field for which to collect unique values
query The query used to select records

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

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

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

Authors

Sönke Ludwig

Copyright

© 2012-2016 RejectedSoftware e.K.

License

Subject to the terms of the MIT license, as written in the included LICENSE.txt file.