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|
// Basic $lookup regression tests.
(function() {
"use strict";
load("jstests/aggregation/extras/utils.js"); // For assertErrorCode.
load("jstests/libs/fixture_helpers.js"); // For isSharded.
load("jstests/noPassthrough/libs/server_parameter_helpers.js"); // For setParameterOnAllHosts.
load("jstests/libs/discover_topology.js"); // For findDataBearingNodes.
const st = new ShardingTest({shards: 2, config: 1, mongos: 1});
const testName = "lookup_sharded";
const nodeList = DiscoverTopology.findNonConfigNodes(st.s);
setParameterOnAllHosts(nodeList, "internalQueryAllowShardedLookup", true);
const mongosDB = st.s0.getDB(testName);
assert.commandWorked(mongosDB.dropDatabase());
// Used by testPipeline to sort result documents. All _ids must be primitives.
function compareId(a, b) {
if (a._id < b._id) {
return -1;
}
if (a._id > b._id) {
return 1;
}
return 0;
}
// Helper for testing that pipeline returns correct set of results.
function testPipeline(pipeline, expectedResult, collection) {
assert.eq(collection.aggregate(pipeline).toArray().sort(compareId),
expectedResult.sort(compareId));
}
function runTest(coll, from, thirdColl, fourthColl) {
let db = null; // Using the db variable is banned in this function.
assert.commandWorked(coll.remove({}));
assert.commandWorked(from.remove({}));
assert.commandWorked(thirdColl.remove({}));
assert.commandWorked(fourthColl.remove({}));
assert.commandWorked(coll.insert({_id: 0, a: 1}));
assert.commandWorked(coll.insert({_id: 1, a: null}));
assert.commandWorked(coll.insert({_id: 2}));
assert.commandWorked(from.insert({_id: 0, b: 1}));
assert.commandWorked(from.insert({_id: 1, b: null}));
assert.commandWorked(from.insert({_id: 2}));
//
// Basic functionality.
//
// "from" document added to "as" field if a == b, where nonexistent fields are treated as
// null.
let expectedResults = [
{_id: 0, a: 1, "same": [{_id: 0, b: 1}]},
{_id: 1, a: null, "same": [{_id: 1, b: null}, {_id: 2}]},
{_id: 2, "same": [{_id: 1, b: null}, {_id: 2}]}
];
testPipeline([{$lookup: {localField: "a", foreignField: "b", from: "from", as: "same"}}],
expectedResults,
coll);
// If localField is nonexistent, it is treated as if it is null.
expectedResults = [
{_id: 0, a: 1, "same": [{_id: 1, b: null}, {_id: 2}]},
{_id: 1, a: null, "same": [{_id: 1, b: null}, {_id: 2}]},
{_id: 2, "same": [{_id: 1, b: null}, {_id: 2}]}
];
testPipeline(
[{$lookup: {localField: "nonexistent", foreignField: "b", from: "from", as: "same"}}],
expectedResults,
coll);
// If foreignField is nonexistent, it is treated as if it is null.
expectedResults = [
{_id: 0, a: 1, "same": []},
{_id: 1, a: null, "same": [{_id: 0, b: 1}, {_id: 1, b: null}, {_id: 2}]},
{_id: 2, "same": [{_id: 0, b: 1}, {_id: 1, b: null}, {_id: 2}]}
];
testPipeline(
[{$lookup: {localField: "a", foreignField: "nonexistent", from: "from", as: "same"}}],
expectedResults,
coll);
// If there are no matches or the from coll doesn't exist, the result is an empty array.
expectedResults =
[{_id: 0, a: 1, "same": []}, {_id: 1, a: null, "same": []}, {_id: 2, "same": []}];
testPipeline(
[{$lookup: {localField: "_id", foreignField: "nonexistent", from: "from", as: "same"}}],
expectedResults,
coll);
testPipeline([{$lookup: {localField: "a", foreignField: "b", from: "nonexistent", as: "same"}}],
expectedResults,
coll);
// If field name specified by "as" already exists, it is overwritten.
expectedResults = [
{_id: 0, "a": [{_id: 0, b: 1}]},
{_id: 1, "a": [{_id: 1, b: null}, {_id: 2}]},
{_id: 2, "a": [{_id: 1, b: null}, {_id: 2}]}
];
testPipeline([{$lookup: {localField: "a", foreignField: "b", from: "from", as: "a"}}],
expectedResults,
coll);
// Running multiple $lookups in the same pipeline is allowed.
expectedResults = [
{_id: 0, a: 1, "c": [{_id: 0, b: 1}], "d": [{_id: 0, b: 1}]},
{_id: 1, a: null, "c": [{_id: 1, b: null}, {_id: 2}], "d": [{_id: 1, b: null}, {_id: 2}]},
{_id: 2, "c": [{_id: 1, b: null}, {_id: 2}], "d": [{_id: 1, b: null}, {_id: 2}]}
];
testPipeline(
[
{$lookup: {localField: "a", foreignField: "b", from: "from", as: "c"}},
{$project: {"a": 1, "c": 1}},
{$lookup: {localField: "a", foreignField: "b", from: "from", as: "d"}}
],
expectedResults,
coll);
//
// Coalescing with $unwind.
//
// A normal $unwind with on the "as" field.
expectedResults = [
{_id: 0, a: 1, same: {_id: 0, b: 1}},
{_id: 1, a: null, same: {_id: 1, b: null}},
{_id: 1, a: null, same: {_id: 2}},
{_id: 2, same: {_id: 1, b: null}},
{_id: 2, same: {_id: 2}}
];
testPipeline(
[
{$lookup: {localField: "a", foreignField: "b", from: "from", as: "same"}},
{$unwind: {path: "$same"}}
],
expectedResults,
coll);
// An $unwind on the "as" field, with includeArrayIndex.
expectedResults = [
{_id: 0, a: 1, same: {_id: 0, b: 1}, index: NumberLong(0)},
{_id: 1, a: null, same: {_id: 1, b: null}, index: NumberLong(0)},
{_id: 1, a: null, same: {_id: 2}, index: NumberLong(1)},
{_id: 2, same: {_id: 1, b: null}, index: NumberLong(0)},
{_id: 2, same: {_id: 2}, index: NumberLong(1)},
];
testPipeline(
[
{$lookup: {localField: "a", foreignField: "b", from: "from", as: "same"}},
{$unwind: {path: "$same", includeArrayIndex: "index"}}
],
expectedResults,
coll);
// Normal $unwind with no matching documents.
expectedResults = [];
testPipeline(
[
{$lookup: {localField: "_id", foreignField: "nonexistent", from: "from", as: "same"}},
{$unwind: {path: "$same"}}
],
expectedResults,
coll);
// $unwind with preserveNullAndEmptyArray with no matching documents.
expectedResults = [
{_id: 0, a: 1},
{_id: 1, a: null},
{_id: 2},
];
testPipeline(
[
{$lookup: {localField: "_id", foreignField: "nonexistent", from: "from", as: "same"}},
{$unwind: {path: "$same", preserveNullAndEmptyArrays: true}}
],
expectedResults,
coll);
// $unwind with preserveNullAndEmptyArray, some with matching documents, some without.
expectedResults = [
{_id: 0, a: 1},
{_id: 1, a: null, same: {_id: 0, b: 1}},
{_id: 2},
];
testPipeline(
[
{$lookup: {localField: "_id", foreignField: "b", from: "from", as: "same"}},
{$unwind: {path: "$same", preserveNullAndEmptyArrays: true}}
],
expectedResults,
coll);
// $unwind with preserveNullAndEmptyArray and includeArrayIndex, some with matching
// documents, some without.
expectedResults = [
{_id: 0, a: 1, index: null},
{_id: 1, a: null, same: {_id: 0, b: 1}, index: NumberLong(0)},
{_id: 2, index: null},
];
testPipeline(
[
{$lookup: {localField: "_id", foreignField: "b", from: "from", as: "same"}},
{$unwind: {path: "$same", preserveNullAndEmptyArrays: true, includeArrayIndex: "index"}}
],
expectedResults,
coll);
//
// Dependencies.
//
// If $lookup didn't add "localField" to its dependencies, this test would fail as the
// value of the "a" field would be lost and treated as null.
expectedResults = [
{_id: 0, "same": [{_id: 0, b: 1}]},
{_id: 1, "same": [{_id: 1, b: null}, {_id: 2}]},
{_id: 2, "same": [{_id: 1, b: null}, {_id: 2}]}
];
testPipeline(
[
{$lookup: {localField: "a", foreignField: "b", from: "from", as: "same"}},
{$project: {"same": 1}}
],
expectedResults,
coll);
// If $lookup didn't add fields referenced by "let" variables to its dependencies, this test
// would fail as the value of the "a" field would be lost and treated as null.
expectedResults = [
{"_id": 0, "same": [{"_id": 0, "x": 1}, {"_id": 1, "x": 1}, {"_id": 2, "x": 1}]},
{"_id": 1, "same": [{"_id": 0, "x": null}, {"_id": 1, "x": null}, {"_id": 2, "x": null}]},
{"_id": 2, "same": [{"_id": 0}, {"_id": 1}, {"_id": 2}]}
];
testPipeline(
[
{
$lookup: {
let : {var1: "$a"},
pipeline: [{$project: {x: "$$var1"}}],
from: "from",
as: "same"
}
},
{$project: {"same": 1}}
],
expectedResults,
coll);
//
// Dotted field paths.
//
assert.commandWorked(coll.remove({}));
assert.commandWorked(coll.insert({_id: 0, a: 1}));
assert.commandWorked(coll.insert({_id: 1, a: null}));
assert.commandWorked(coll.insert({_id: 2}));
assert.commandWorked(coll.insert({_id: 3, a: {c: 1}}));
assert.commandWorked(from.remove({}));
assert.commandWorked(from.insert({_id: 0, b: 1}));
assert.commandWorked(from.insert({_id: 1, b: null}));
assert.commandWorked(from.insert({_id: 2}));
assert.commandWorked(from.insert({_id: 3, b: {c: 1}}));
assert.commandWorked(from.insert({_id: 4, b: {c: 2}}));
// Once without a dotted field.
let pipeline = [{$lookup: {localField: "a", foreignField: "b", from: "from", as: "same"}}];
expectedResults = [
{_id: 0, a: 1, "same": [{_id: 0, b: 1}]},
{_id: 1, a: null, "same": [{_id: 1, b: null}, {_id: 2}]},
{_id: 2, "same": [{_id: 1, b: null}, {_id: 2}]},
{_id: 3, a: {c: 1}, "same": [{_id: 3, b: {c: 1}}]}
];
testPipeline(pipeline, expectedResults, coll);
// Look up a dotted field.
pipeline = [{$lookup: {localField: "a.c", foreignField: "b.c", from: "from", as: "same"}}];
// All but the last document in 'coll' have a nullish value for 'a.c'.
expectedResults = [
{_id: 0, a: 1, same: [{_id: 0, b: 1}, {_id: 1, b: null}, {_id: 2}]},
{_id: 1, a: null, same: [{_id: 0, b: 1}, {_id: 1, b: null}, {_id: 2}]},
{_id: 2, same: [{_id: 0, b: 1}, {_id: 1, b: null}, {_id: 2}]},
{_id: 3, a: {c: 1}, same: [{_id: 3, b: {c: 1}}]}
];
testPipeline(pipeline, expectedResults, coll);
// With an $unwind stage.
assert.commandWorked(coll.remove({}));
assert.commandWorked(coll.insert({_id: 0, a: {b: 1}}));
assert.commandWorked(coll.insert({_id: 1}));
assert.commandWorked(from.remove({}));
assert.commandWorked(from.insert({_id: 0, target: 1}));
pipeline = [
{
$lookup: {
localField: "a.b",
foreignField: "target",
from: "from",
as: "same.documents",
}
},
{
// Expected input to $unwind:
// {_id: 0, a: {b: 1}, same: {documents: [{_id: 0, target: 1}]}}
// {_id: 1, same: {documents: []}}
$unwind: {
path: "$same.documents",
preserveNullAndEmptyArrays: true,
includeArrayIndex: "c.d.e",
}
}
];
expectedResults = [
{_id: 0, a: {b: 1}, same: {documents: {_id: 0, target: 1}}, c: {d: {e: NumberLong(0)}}},
{_id: 1, same: {}, c: {d: {e: null}}},
];
testPipeline(pipeline, expectedResults, coll);
//
// Query-like local fields (SERVER-21287)
//
// This must only do an equality match rather than treating the value as a regex.
assert.commandWorked(coll.remove({}));
assert.commandWorked(coll.insert({_id: 0, a: /a regex/}));
assert.commandWorked(from.remove({}));
assert.commandWorked(from.insert({_id: 0, b: /a regex/}));
assert.commandWorked(from.insert({_id: 1, b: "string that matches /a regex/"}));
pipeline = [
{
$lookup: {
localField: "a",
foreignField: "b",
from: "from",
as: "b",
}
},
];
expectedResults = [{_id: 0, a: /a regex/, b: [{_id: 0, b: /a regex/}]}];
testPipeline(pipeline, expectedResults, coll);
//
// A local value of an array.
//
// Basic array corresponding to multiple documents.
assert.commandWorked(coll.remove({}));
assert.commandWorked(coll.insert({_id: 0, a: [0, 1, 2]}));
assert.commandWorked(from.remove({}));
assert.commandWorked(from.insert({_id: 0}));
assert.commandWorked(from.insert({_id: 1}));
pipeline = [
{
$lookup: {
localField: "a",
foreignField: "_id",
from: "from",
as: "b",
}
},
];
expectedResults = [{_id: 0, a: [0, 1, 2], b: [{_id: 0}, {_id: 1}]}];
testPipeline(pipeline, expectedResults, coll);
// Basic array corresponding to a single document.
assert.commandWorked(coll.remove({}));
assert.commandWorked(coll.insert({_id: 0, a: [1]}));
assert.commandWorked(from.remove({}));
assert.commandWorked(from.insert({_id: 0}));
assert.commandWorked(from.insert({_id: 1}));
pipeline = [
{
$lookup: {
localField: "a",
foreignField: "_id",
from: "from",
as: "b",
}
},
];
expectedResults = [{_id: 0, a: [1], b: [{_id: 1}]}];
testPipeline(pipeline, expectedResults, coll);
// Array containing regular expressions.
assert.commandWorked(coll.remove({}));
assert.commandWorked(coll.insert({_id: 0, a: [/a regex/, /^x/]}));
assert.commandWorked(coll.insert({_id: 1, a: [/^x/]}));
assert.commandWorked(from.remove({}));
assert.commandWorked(from.insert({_id: 0, b: "should not match a regex"}));
assert.commandWorked(from.insert({_id: 1, b: "xxxx"}));
assert.commandWorked(from.insert({_id: 2, b: /a regex/}));
assert.commandWorked(from.insert({_id: 3, b: /^x/}));
pipeline = [
{
$lookup: {
localField: "a",
foreignField: "b",
from: "from",
as: "b",
}
},
];
expectedResults = [
{_id: 0, a: [/a regex/, /^x/], b: [{_id: 2, b: /a regex/}, {_id: 3, b: /^x/}]},
{_id: 1, a: [/^x/], b: [{_id: 3, b: /^x/}]}
];
testPipeline(pipeline, expectedResults, coll);
// 'localField' references a field within an array of sub-objects.
assert.commandWorked(coll.remove({}));
assert.commandWorked(coll.insert({_id: 0, a: [{b: 1}, {b: 2}]}));
assert.commandWorked(from.remove({}));
assert.commandWorked(from.insert({_id: 0}));
assert.commandWorked(from.insert({_id: 1}));
assert.commandWorked(from.insert({_id: 2}));
assert.commandWorked(from.insert({_id: 3}));
pipeline = [
{
$lookup: {
localField: "a.b",
foreignField: "_id",
from: "from",
as: "c",
}
},
];
expectedResults = [{"_id": 0, "a": [{"b": 1}, {"b": 2}], "c": [{"_id": 1}, {"_id": 2}]}];
testPipeline(pipeline, expectedResults, coll);
//
// Test $lookup when the foreign collection is a view.
//
// TODO SERVER-32548: Allow this test to run when the foreign collection is sharded.
if (!FixtureHelpers.isSharded(from)) {
assert.commandWorked(
coll.getDB().runCommand({create: "fromView", viewOn: "from", pipeline: []}));
pipeline = [
{
$lookup: {
localField: "a.b",
foreignField: "_id",
from: "fromView",
as: "c",
}
},
];
expectedResults = [{"_id": 0, "a": [{"b": 1}, {"b": 2}], "c": [{"_id": 1}, {"_id": 2}]}];
testPipeline(pipeline, expectedResults, coll);
}
//
// Error cases.
//
// 'from', 'as', 'localField' and 'foreignField' must all be specified when run with
// localField/foreignField syntax.
assertErrorCode(
coll, [{$lookup: {foreignField: "b", from: "from", as: "same"}}], ErrorCodes.FailedToParse);
assertErrorCode(
coll, [{$lookup: {localField: "a", from: "from", as: "same"}}], ErrorCodes.FailedToParse);
assertErrorCode(coll,
[{$lookup: {localField: "a", foreignField: "b", as: "same"}}],
ErrorCodes.FailedToParse);
assertErrorCode(coll,
[{$lookup: {localField: "a", foreignField: "b", from: "from"}}],
ErrorCodes.FailedToParse);
// localField/foreignField and pipeline/let syntax must not be mixed.
assertErrorCode(coll,
[{$lookup: {pipeline: [], foreignField: "b", from: "from", as: "as"}}],
ErrorCodes.FailedToParse);
assertErrorCode(coll,
[{$lookup: {pipeline: [], localField: "b", from: "from", as: "as"}}],
ErrorCodes.FailedToParse);
assertErrorCode(
coll,
[{$lookup: {pipeline: [], localField: "b", foreignField: "b", from: "from", as: "as"}}],
ErrorCodes.FailedToParse);
assertErrorCode(coll,
[{$lookup: {let : {a: "$b"}, foreignField: "b", from: "from", as: "as"}}],
ErrorCodes.FailedToParse);
assertErrorCode(coll,
[{$lookup: {let : {a: "$b"}, localField: "b", from: "from", as: "as"}}],
ErrorCodes.FailedToParse);
assertErrorCode(
coll,
[{$lookup: {let : {a: "$b"}, localField: "b", foreignField: "b", from: "from", as: "as"}}],
ErrorCodes.FailedToParse);
// 'from', 'as', 'localField' and 'foreignField' must all be of type string.
assertErrorCode(coll,
[{$lookup: {localField: 1, foreignField: "b", from: "from", as: "as"}}],
ErrorCodes.FailedToParse);
assertErrorCode(coll,
[{$lookup: {localField: "a", foreignField: 1, from: "from", as: "as"}}],
ErrorCodes.FailedToParse);
assertErrorCode(coll,
[{$lookup: {localField: "a", foreignField: "b", from: 1, as: "as"}}],
ErrorCodes.FailedToParse);
assertErrorCode(coll,
[{$lookup: {localField: "a", foreignField: "b", from: "from", as: 1}}],
ErrorCodes.FailedToParse);
// The foreign collection must be a valid namespace.
assertErrorCode(coll,
[{$lookup: {localField: "a", foreignField: "b", from: "", as: "as"}}],
ErrorCodes.InvalidNamespace);
// $lookup's field must be an object.
assertErrorCode(coll, [{$lookup: "string"}], ErrorCodes.FailedToParse);
}
//
// Test unsharded local collection and unsharded foreign collection.
//
mongosDB.lookUp.drop();
mongosDB.from.drop();
mongosDB.thirdColl.drop();
mongosDB.fourthColl.drop();
runTest(mongosDB.lookUp, mongosDB.from, mongosDB.thirdColl, mongosDB.fourthColl);
// Verify that the command is sent only to the primary shard when both the local and foreign
// collections are unsharded.
assert(
!assert
.commandWorked(mongosDB.lookup.explain().aggregate([{
$lookup:
{from: mongosDB.from.getName(), localField: "a", foreignField: "b", as: "results"}
}]))
.hasOwnProperty("shards"));
// Enable sharding on the test DB and ensure its primary is shard0000.
assert.commandWorked(mongosDB.adminCommand({enableSharding: mongosDB.getName()}));
st.ensurePrimaryShard(mongosDB.getName(), st.shard0.shardName);
//
// Test unsharded local collection and sharded foreign collection.
//
// Shard the foreign collection on _id.
st.shardColl(mongosDB.from, {_id: 1}, {_id: 0}, {_id: 1}, mongosDB.getName());
runTest(mongosDB.lookUp, mongosDB.from, mongosDB.thirdColl, mongosDB.fourthColl);
//
// Test sharded local collection and unsharded foreign collection.
//
assert(mongosDB.from.drop());
// Shard the local collection on _id.
st.shardColl(mongosDB.lookup, {_id: 1}, {_id: 0}, {_id: 1}, mongosDB.getName());
runTest(mongosDB.lookUp, mongosDB.from, mongosDB.thirdColl, mongosDB.fourthColl);
//
// Test sharded local and foreign collections.
//
// Shard the foreign collection on _id.
st.shardColl(mongosDB.from, {_id: 1}, {_id: 0}, {_id: 1}, mongosDB.getName());
runTest(mongosDB.lookUp, mongosDB.from, mongosDB.thirdColl, mongosDB.fourthColl);
// Test that a $lookup from an unsharded collection followed by a $merge to a sharded collection
// is allowed.
const sourceColl = st.getDB(testName).lookUp;
assert(sourceColl.drop());
assert(st.adminCommand({shardCollection: sourceColl.getFullName(), key: {_id: "hashed"}}));
assert.commandWorked(sourceColl.insert({_id: 0, a: 0}));
const outColl = st.getDB(testName).out;
assert(outColl.drop());
assert(st.adminCommand({shardCollection: outColl.getFullName(), key: {_id: "hashed"}}));
const fromColl = st.getDB(testName).from;
assert(fromColl.drop());
assert.commandWorked(fromColl.insert({_id: 0, b: 0}));
sourceColl.aggregate([
{$lookup: {localField: "a", foreignField: "b", from: fromColl.getName(), as: "same"}},
{$merge: {into: outColl.getName()}}
]);
assert.eq([{a: 0, same: [{_id: 0, b: 0}]}], outColl.find({}, {_id: 0}).toArray());
// Disable the server parameter. Be sure that an attempt to run a $lookup on a sharded
// collection fails.
setParameterOnAllHosts(nodeList, "internalQueryAllowShardedLookup", false);
// Re shard the foreign collection on _id.
st.shardColl(mongosDB.from, {_id: 1}, {_id: 0}, {_id: 1}, mongosDB.getName());
let err = assert.throws(
() =>
sourceColl
.aggregate([{
$lookup: {localField: "a", foreignField: "b", from: fromColl.getName(), as: "same"}
}])
.itcount());
assert.eq(err.code, 28769);
err = assert.throws(
() => sourceColl
.aggregate(
[{
$lookup:
{localField: "a", foreignField: "b", from: fromColl.getName(), as: "same"}
}],
{allowDiskUse: true})
.itcount());
assert.eq(err.code, 28769);
err = assert.throws(() => sourceColl
.aggregate(
[
{$_internalSplitPipeline: {mergeType: "anyShard"}},
{
$lookup: {
localField: "a",
foreignField: "b",
from: fromColl.getName(),
as: "same"
}
}
],
{allowDiskUse: true})
.itcount());
assert.eq(err.code, 28769);
err = assert.throws(
() => sourceColl
.aggregate(
[{$facet: {
a: {
$lookup:
{localField: "a", foreignField: "b", from: fromColl.getName(), as: "same"}
}
}}],
{allowDiskUse: true})
.itcount());
assert.eq(err.code, 40170);
st.stop();
}());
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