I have an array of objects with only ObjectIDs and want to search a collection for all the documents with those IDs.
我有一个对象数组，只使用ObjectIDs，并希望用这些id搜索所有文档的集合。
var array = [{ _id: 5551e59be360594cd3319644 },
{ _id: 5551e59be360594cd3319631 },
{ _id: 5551e59be360594cd33195d2 },
{ _id: 5551e59be360594cd3319627 }];
Here is what I'm currently doing to get my result:
以下是我目前正在做的，以得到我的结果:
for (var i = 0; i < array.length; i++) {
db.collection('test').findOne({_id:array[i]._id}, function(err, matched) {
console.log(matched);
});
I tried to work with the $inoperator but had no success because it's not an array of IDs but an array of objects with those IDs inside.
我尝试使用$inoperator，但没有成功，因为它不是一个IDs数组，而是一个包含了这些id的对象数组。
Is there another way to do this with just one database query as I don't think it's a great idea to do so many database queries in a for loop.
是否有另一种方法可以只使用一个数据库查询，因为我认为在for循环中执行这么多数据库查询不是一个好主意。
EDIT I now tried it with the map method (like @chrisdam explained) so I have an array of the IDs but when i pass it to the find method i get this result:
我现在尝试使用map方法(如@chrisdam解释)，所以我有一个id数组，但是当我将它传递给find方法时，我得到了这个结果:
EDIT2 Nevermind my first edit. find() returns just a cursor, not the documents itself. So I used toArray(). Thanks for your help @chrisdam!!
EDIT2不在乎我的第一次编辑。find()只返回一个游标，而不是文档本身。所以我使用toArray()。谢谢你的帮助@chrisdam!
{ db:
{ domain: null,
_events: {},
_maxListeners: undefined,
databaseName: 'test',
serverConfig: {
domain: null,
_events: {},
_maxListeners: undefined,
auth: [Getter],
_callBackStore: [Object],
_commandsStore: [Object],
_dbStore: [Object],
host: 'localhost',
port: 27017,
options: [Object],
internalMaster: true,
connected: true,
poolSize: 5,
disableDriverBSONSizeCheck: false,
_used: true,
replicasetInstance: null,
emitOpen: false,
ssl: false,
sslValidate: false,
sslCA: null,
sslCert: undefined,
sslKey: undefined,
sslPass: undefined,
serverCapabilities: [Object],
name: 'localhost:27017',
socketOptions: [Object],
logger: [Object],
eventHandlers: [Object],
_serverState: 'connected',
_state: [Object],
recordQueryStats: false,
socketTimeoutMS: [Getter/Setter],
_readPreference: [Object],
db: [Circular],
dbInstances: [Object],
connectionPool: [Object],
isMasterDoc: [Object] },
options: {
read_preference_tags: null,
read_preference: 'primary',
url: 'mongodb://localhost:27017/test',
native_parser: true,
readPreference: [Object],
safe: false,
w: 1 },
_applicationClosed: false,
slaveOk: false,
bufferMaxEntries: -1,
native_parser: true,
bsonLib: {
BSON: [Object],
Long: [Object],
ObjectID: [Object],
DBRef: [Object],
Code: [Object],
Timestamp: [Object],
Binary: [Object],
Double: [Object],
MaxKey: [Object],
MinKey: [Object],
Symbol: [Object] },
bson: { promoteLongs: true },
bson_deserializer: {
Code: [Object],
Symbol: [Object],
BSON: [Object],
DBRef: [Object],
Binary: [Object],
ObjectID: [Object],
Long: [Object],
Timestamp: [Object],
Double: [Object],
MinKey: [Object],
MaxKey: [Object],
promoteLongs: true },
bson_serializer: {
Code: [Object],
Symbol: [Object],
BSON: [Object],
DBRef: [Object],
Binary: [Object],
ObjectID: [Object],
Long: [Object],
Timestamp: [Object],
Double: [Object],
MinKey: [Object],
MaxKey: [Object],
promoteLongs: true },
_state: 'connected',
pkFactory: {
[Function: ObjectID]
index: 13651524,
createPk: [Function: createPk],
createFromTime: [Function: createFromTime],
createFromHexString: [Function: createFromHexString],
isValid: [Function: isValid],
ObjectID: [Circular],
ObjectId: [Circular] },
forceServerObjectId: false,
safe: false,
notReplied: {},
isInitializing: true,
openCalled: true,
commands: [],
logger: { error: [Function], log: [Function], debug: [Function] },
tag: 1431517732801,
eventHandlers: {
error: [],
parseError: [],
poolReady: [],
message: [],
close: [] },
serializeFunctions: false,
raw: false,
recordQueryStats: false,
retryMiliSeconds: 1000,
numberOfRetries: 60,
readPreference: { _type: 'ReadPreference', mode: 'primary', tags: undefined } },
collection: {
db: {
domain: null,
_events: {},
_maxListeners: undefined,
databaseName: 'test',
serverConfig: [Object],
options: [Object],
_applicationClosed: false,
slaveOk: false,
bufferMaxEntries: -1,
native_parser: true,
bsonLib: [Object],
bson: [Object],
bson_deserializer: [Object],
bson_serializer: [Object],
_state: 'connected',
pkFactory: [Object],
forceServerObjectId: false,
safe: false,
notReplied: {},
isInitializing: true,
openCalled: true,
commands: [],
logger: [Object],
tag: 1431517732801,
eventHandlers: [Object],
serializeFunctions: false,
raw: false,
recordQueryStats: false,
retryMiliSeconds: 1000,
numberOfRetries: 60,
readPreference: [Object] },
collectionName: 'sick',
internalHint: null,
opts: {},
slaveOk: false,
serializeFunctions: false,
raw: false,
readPreference: { _type: 'ReadPreference', mode: 'primary', tags: undefined },
pkFactory: {
[Function: ObjectID]
index: 13651524,
createPk: [Function: createPk],
createFromTime: [Function: createFromTime],
createFromHexString: [Function: createFromHexString],
isValid: [Function: isValid],
ObjectID: [Circular],
ObjectId: [Circular] },
serverCapabilities: undefined },
selector: { _id: { '$in': [Object] } },
fields: undefined,
skipValue: 0,
limitValue: 0,
sortValue: undefined,
hint: null,
explainValue: undefined,
snapshot: undefined,
timeout: true,
tailable: undefined,
awaitdata: undefined,
oplogReplay: undefined,
numberOfRetries: 5,
currentNumberOfRetries: 5,
batchSizeValue: 0,
raw: false,
readPreference: { _type: 'ReadPreference', mode: 'primary', tags: undefined },
returnKey: undefined,
maxScan: undefined,
min: undefined,
max: undefined,
showDiskLoc: undefined,
comment: undefined,
tailableRetryInterval: 100,
exhaust: false,
partial: false,
slaveOk: false,
maxTimeMSValue: undefined,
connection: undefined,
transforms: undefined,
totalNumberOfRecords: 0,
items: [],
cursorId: { _bsontype: 'Long', low_: 0, high_: 0 },
dbName: undefined,
state: 0,
queryRun: false,
getMoreTimer: false,
collectionName: 'test.sick' }
1 个解决方案
#1
4
You could try the JavaScript's native map method to generate an ObjectIds array that you can then use with the $in operator as follows:
您可以尝试使用JavaScript的本机映射方法生成一个objective - array，然后使用$in操作符，如下所示:
var array = [{ _id: "5551e59be360594cd3319644" },
{ _id: "5551e59be360594cd3319631" },
{ _id: "5551e59be360594cd33195d2" },
{ _id: "5551e59be360594cd3319627" }],
ids = array.map(function (obj){ return ObjectId(obj._id)});
db.collection.find({ "_id": { "$in": ids }});
OR just use the $or operator as:
或者使用$或操作符:
var array = [{ _id: "5551e59be360594cd3319644" },
{ _id: "5551e59be360594cd3319631" },
{ _id: "5551e59be360594cd33195d2" },
{ _id: "5551e59be360594cd3319627" }],
ids = array.map(function (obj){ return { _id: ObjectId(obj._id) } });
db.collection.find({ "$or": ids });
#1
4
You could try the JavaScript's native map method to generate an ObjectIds array that you can then use with the $in operator as follows:
您可以尝试使用JavaScript的本机映射方法生成一个objective - array，然后使用$in操作符，如下所示:
var array = [{ _id: "5551e59be360594cd3319644" },
{ _id: "5551e59be360594cd3319631" },
{ _id: "5551e59be360594cd33195d2" },
{ _id: "5551e59be360594cd3319627" }],
ids = array.map(function (obj){ return ObjectId(obj._id)});
db.collection.find({ "_id": { "$in": ids }});
OR just use the $or operator as:
或者使用$或操作符:
var array = [{ _id: "5551e59be360594cd3319644" },
{ _id: "5551e59be360594cd3319631" },
{ _id: "5551e59be360594cd33195d2" },
{ _id: "5551e59be360594cd3319627" }],
ids = array.map(function (obj){ return { _id: ObjectId(obj._id) } });
db.collection.find({ "$or": ids });