mongoose - MongoDB Query Based on ObjectId Reference Condition -

-

मेरे पास MongoDB संग्रह बिल्लियों है जिसके पास एक ObjectId संदर्भ फ़ील्ड है zooId संग्रह चिड़ियाघर ।

मैं कैसे की तरह कुछ पूछताछ के बारे में जाना होगा

db.Cats.find ({zooId.zooName: 'San डिएगो '}) गिनती ()

जहां क्वेरी की स्थिति zooName में zooId संदर्भ में है? < / P>

मैं मोंगोज का उपयोग करके समझता हूं, मैं कुछ संदर्भों को वास्तव में लाने के लिए populate विधि को कॉल कर सकता हूं, लेकिन मैं मोंगॉड कंसोल या रोबोमोंगो में सीधे कैसे इसी तरह की बातें करूँगा?

धन्यवाद!

"post-text" itemprop = "text">

सरल कोडिंग: 

  var cats = 0; Db.Zoo.find ({zooName: 'San Diego'}) .पूर्व (फ़ंक्शन (zooItem) {var id = zooItem._id; cats + = db.Cat.find ({'zooId': id})। गणना ( );}); प्रिंट (बिल्लियों);

Comments

Post a Comment

Popular posts from this blog

c# - SignalR: "Protocol error: Unknown transport." when navigating to hub -

-
Image
I am trying to use the ASP.NET signal for the first time - here's what I did: created a new web Has been added to the project and the following signal R packages: I have created the following category: [Hub-name ("chat")] Public class ChatHub: Hub {Public Zero Halo () {Clients.All.hello ( ); }} and the following startup configuration: public partial class startup {public zero configuration (IAppBuilder app) {configure (app); App.MapSignalR (); }} However, whenever I navigate localhost: (port) / api / signalr / chat I get the following error: Protocol error: Unknown transport. I am running a new browser and trying different people so remove it from the API / URL, and just use the localhost: (potter) / signaller / Chat
Read more

class - Kivy: how to instantiate a dynamic classes in python -

-
Using KV lang on my Python code, I have taken a hard time trying to instantiate a dynamic class, the following Consider the code: My test.kv file looks like this: & lt; MyPopup @ popup: Title: 'Hello' size_hunt: (1, .6) Grid layout: ID: RouteGrid column: 2 padding: ['8dp', '4dp', '8dp', '4dp'] Difference: '8dp' label: text: 'some text here' button: text: 'OK' On_press: do_something () & lt; MyGrid & gt;: Rows: 1 Button: Text: 'Show Popup' on_press: root.pop.show () Then import Kivy.app into my test.py: I get the following error: raise Factory Exception ('Uncount Class' '% name) kivy.factory.FactoryException: Unknown class Can anyone tell me how to do this properly, what do I remember? If you need more information please let me know Thank you. Takes a call to the factory before the KV file is loaded, so you want the class to Are not yet in existence. As long as no clas...
Read more

svn - Cannot merge back into trunk, must be ancestrally related. But they *are* related as far as I understand -

-
Image
So I'm trying to merge back into my trunk, but I'm getting errors saying that I Because they are not related to the ancestors but I am not clear why this is why. Here is the graph generated by TartiSesWN The trunk is at the bottom left (14698) Currently, I am starting with the merger in the trunk (15 9 7 9) from the top right, this is an example which claims that it is not related to the ancestors, some disparities in it That is what a coworker presented, and I'm not sure it could be the reason for this. If you notice, in the right middle, the branch with modification number 15406 actually divides a tag. It seems incredibly wrong to me, but I'm not sure. A few months ago the coworker did this (he does not work here anymore). However, they should be related to all ancestors because they come from all trunk, right? If this is true, then why am I getting this error? Will a tag be divided? The head of the trunk is 16063 (as per the figure), 14698 merge-s...
Read more