How to access a preexisting collection with Mongoose

Question

I have a large collection of 300 question objects in a database test  I can interact with this collection easily through MongoDB s interactive shell  however  when I try to get the collection through Mongoose in an express js application I get an empty array   My question is  how can I access this already existing dataset instead of recreating it in express  Here s some code   var mongoose   require  mongoose    var Schema   mongoose Schema   mongoose connect  mongodb   localhost test    mongoose model  question   new Schema   url  String  text  String  id  Number       var questions   mongoose model  question    questions find     function err  data    console log err  data  data length         This outputs   null    0

User · Accepted Answer

Mongoose added the ability to specify the collection name under the schema, or as the third argument when declaring the model. Otherwise it will use the pluralized version given by the name you map to the model.

Try something like the following, either schema-mapped:

new Schema({ url: String, text: String, id: Number}, 
           { collection : 'question' });   // collection name

or model mapped:

mongoose.model('Question', 
               new Schema({ url: String, text: String, id: Number}), 
               'question');     // collection name

User · Answer

You can do something like this  than you you ll access the native mongodb functions inside mongoose   var mongoose   require  mongoose    mongoose connect  mongodb   localhost local     var connection   mongoose connection   connection on  error   console error bind console   connection error      connection once  open   function           connection db collection  YourCollectionName   function err  collection           collection find     toArray function err  data               console log data      it will print your collection data

User · Answer

Something else that was not obvious  to me at least  was that the when using Mongoose s third parameter to avoid replacing the actual collection with a new one with the same name  the new Schema      is actually only a placeholder  and doesn t interfere with the exisitng schema so  var User   mongoose model  User   new Schema   url  String  text  String  id  Number     collection    users            collection name  User find     function err  data    console log err  data  data length        works fine and returns all fields - even if the actual  remote  Schema contains none of these fields  Mongoose will still want it as new Schema       and a variable almost certainly won t hack it

User · Answer

Here s an abstraction of Will Nathan s answer if anyone just wants an easy copy-paste add-in function   function find  name  query  cb        mongoose connection db collection name  function  err  collection           collection find query  toArray cb              simply do find collection name  query  callback   to be given the result   for example  if I have a document   a   1   in a collection  foo  and I want to list its properties  I do this   find  foo    a   1   function  err  docs                console dir docs                 output       id  4e22118fb83406f66a159da5  a  1

User · Answer

Are you sure you ve connected to the db   I ask because I don t see a port specified   try   mongoose connection on  open   function      console log  mongodb is connected            Also  you can do a  show collections  in mongo shell to see the collections within your db - maybe try adding a record via mongoose and see where it ends up   From the look of your connection string  you should see the record in the  test  db   Hope it helps

User · Answer

I had the same problem and was able to run a schema-less query using an existing Mongoose connection with the code below   I ve added a simple constraint  a b  to show where you would add such a constraint   var action   function  err  collection           Locate all the entries using find     collection find   a   b    toArray function err  results               whatever you want to do with the results in node such as the following              res render  home                       title    MyTitle                     data   results                                         mongoose connection db collection  question   action

User · Answer

Go to MongoDB website  Login  gt  Connect  gt  Connect Application  gt  Copy  gt  Paste in  database url   gt  Collections  gt  Copy Paste in  collection    var mongoose   require  quot mongoose quot    mongoose connect   database url     var conn   mongoose connection  conn on  error   console error bind console   connection error      conn once  open   function       conn db collection  quot  collection  quot   function err  collection        collection find     toArray function err  data           console log data      data printed in console                 Happy to Help   by RTTSS

[mongodb] How to access a preexisting collection with Mongoose?

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