mongodb - Monodb database migration with embedded query -

-

Currently the messages objects in my database are set as the following. "Message": "Message": "System", "Message": "Sean Collahne has entered the room.", "Time": 1406479167270, "Type": "System_ Message", "Room I want to migrate my data basically so that in each message the room id will be displayed in every message: "Helloorom", "_ID": "4IHHHMMGJNTTHWW"}

Yes, that indicates in the appropriate room. Currently it is done with the room attribute, which I see for some reason in my own way.

The objects in my room are set in such a way. 

  {"_id:" xxxxxxxxx "room_name:" "testroom"}

So I was hoping that there was a way to run a liner The correct room id is set for the current message based on the current room attribute which will simply add

I was thinking like something ..

db.messages.update ({}, {$ set: {roomId: db.rooms.findOne ({room_name: cell}) ._ id}})

Now, I'm getting a room is not defined, which makes sense but I do not think this is right, and this It is possible that one-line queries may not be possible.

As you found, this is not possible in a one-line query because you can not access data from two collections Need to join

Here is an example that Mongo shell: 

  db.messages.find ({roomId: {$ exists: wrong}}) .for eka (function (room) {var roomId = db.rooms (one room: name: room.room}); if (room id.id) {db.messages.update ({_id: room._id}, { $ Set: {roomId: roomId._id}}}})

You can clear this with some error checking, and for updates to large archives (MongoDB 2.6 + ).


Comments

Post a Comment

Popular posts from this blog

java - org.apache.http.ProtocolException: Target host is not specified -

-
I have written a simple httprequest / response code and I am getting this error below: I used to type in my classpath httpclient, httpcore, common -Codecs and general logging. I am very new to Java and I do not know what's going on here. Please help me. code: import org.apache.http.client.HttpClient; Import org.apache.http.client.methods.HttpGet; Import org.apache.http.HttpResponse; Import org.apache.http.impl.client.HttpClientBuilder; Import org.apache.http.Header; Import org.apache.http.HttpHeaders; Public class UnshorteningUrl {public static zero main (string [] args throws exception {HttpGet request = zero; HTTP Client Client = HTTP ClientBuilder.credit (). Build (); Try {Request = New HTTP Gate ("trib.me/1lBFzSi"); HttpResponse httpResponse = client.execute (request); Header [] header = httpResponse.getHeaders (HttpHeaders.LOCATION); // Preconditions.checkState (headers.length == 1); String new url = header [0] .getValue (); System.out.println ("new url...
Read more

java - Gradle dependencies: compile project by relative path -

-
Is it possible to specify a dependency on another gradeal project in the granular (in android studios) outside the current project limits? For example, with a relative path like this: dependence {collection project ('../../ stdlib / dagger'}} MyApp (path / user / foo / workspace / mypad) The app (Path / User / Foo / Workspace / MyPass / App) And I have an Android Library Project with 3 subdomules: stdlib (path is / user / foo / Utilities (Path / User / Foo / Workspace / Stadlib / Utilis) http (Path / User / Foo / Workspace / Stadlib / HT) / Li> What I have to do is compile the Dagger, Util, http module in the MyApp project. The Stidelib Library module under heavy development And MyApp will grow in the form of Growth, so I do not want to push them into a Mewen repository. I am a little change. is likely to add another Gredle projects in some way? I will push the study library into the Maven repository after the source is in search of a temp...
Read more

ruby on rails - Object doesn't support #inspect when used with .include -

-
So I have participated in a glitch error that I do not even know how to debug. I am very new to the railing, so it has kicked my ass well when I use the .includes (school) seen by the student, it gives a blue box error, But when I look at any other model and .includes (school) , the school works just fine. class student & lt; ActiveRecord :: Base has has_many: relationships, foreign_key: "liker_id", dependent :: has_many: matches, foreign_key: "student_1_id", dependent :: deleted belong_to: school belong_to: conference belong_to: would_you_rather belong_to: home city belong_to: year is_to: Major and class school & lt; on the console activatecord :: Affiliate for the base: conference includes: respondent, class: "school", foreign_key: "rival_id" (e.g. For: School) Select SQL generated Select "School". * "School" from "school" "ID" IN (1) error message back NoMethodError: u...
Read more