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// Cannot implicitly shard accessed collections as $lookup does not support sharded target
// collection.
// @tags: [assumes_unsharded_collection]
/**
* Confirms that $lookup with a non-correlated foreign pipeline returns expected results.
*/
(function() {
"use strict";
const testDB = db.getSiblingDB("lookup_non_correlated");
const localName = "local";
const localColl = testDB.getCollection(localName);
localColl.drop();
const foreignName = "foreign";
const foreignColl = testDB.getCollection(foreignName);
foreignColl.drop();
assert.writeOK(localColl.insert({_id: "A"}));
assert.writeOK(localColl.insert({_id: "B"}));
assert.writeOK(localColl.insert({_id: "C"}));
assert.writeOK(foreignColl.insert({_id: 1}));
assert.writeOK(foreignColl.insert({_id: 2}));
assert.writeOK(foreignColl.insert({_id: 3}));
// Basic non-correlated lookup returns expected results.
let cursor = localColl.aggregate([
{$match: {_id: {$in: ["B", "C"]}}},
{$sort: {_id: 1}},
{$lookup: {from: foreignName, as: "foreignDocs", pipeline: [{$match: {_id: {"$gte": 2}}}]}},
]);
assert(cursor.hasNext());
assert.docEq({_id: "B", foreignDocs: [{_id: 2}, {_id: 3}]}, cursor.next());
assert(cursor.hasNext());
assert.docEq({_id: "C", foreignDocs: [{_id: 2}, {_id: 3}]}, cursor.next());
assert(!cursor.hasNext());
// Non-correlated lookup followed by unwind on 'as' returns expected results.
cursor = localColl.aggregate([
{$match: {_id: "A"}},
{$lookup: {from: foreignName, as: "foreignDocs", pipeline: [{$match: {_id: {"$gte": 2}}}]}},
{$unwind: "$foreignDocs"}
]);
assert(cursor.hasNext());
assert.docEq({_id: "A", foreignDocs: {_id: 2}}, cursor.next());
assert(cursor.hasNext());
assert.docEq({_id: "A", foreignDocs: {_id: 3}}, cursor.next());
assert(!cursor.hasNext());
// Non-correlated lookup followed by unwind and filter on 'as' returns expected results.
cursor = localColl.aggregate([
{$match: {_id: "A"}},
{$lookup: {from: foreignName, as: "foreignDocs", pipeline: [{$match: {_id: {"$gte": 2}}}]}},
{$unwind: "$foreignDocs"},
{$match: {"foreignDocs._id": 2}}
]);
assert(cursor.hasNext());
assert.docEq({_id: "A", foreignDocs: {_id: 2}}, cursor.next());
assert(!cursor.hasNext());
})();
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