How to use manual references when inserting and retrieving relational data using MongoDb and its C# driver -


as may obvious of question, coming relational database way of thinking (sql server) , using orms (entity framework). want same things in mongodb , having troubles it.

let me explain simple scenario. suppose have user, , each user can write posts (a one-to-many relationship in sql). working simple case.

i've read 2 or 3 articles (and mongodb's original documentation) when use manual references , dbrefs , when embed documents within each other. , here going needing posts without users (like when visitor of website wants see posts) , users without posts (like managing user profiles or something), believe these 2 entities (documents) should separated.

now let's our hands little dirty code. in entity framework implement idea above this:

//user model public class user  {     public int id { get;set; }     public string name { get; set; }     public list<post> posts { get; set; }      public user     {         this.posts = new list<post>();     } }  //post model public class post {     public int id { get; set; }     public string body { get; set; }     public datetime datecreated { get; set; }     public user user { get; set; } }  //getting data pretty easy using entity framework //suppose context created beforehand var usersandtheirposts = context.users.include(x => x.posts).where(x => x.id > 5).tolist();  //getting first users post list<post> firstuserposts = usersandtheirposts.firstordefault().posts;  //updating posts have been created after date x foreach (var post in firstusersposts.where(x => x.datacreated > datex)) {     //do posts } context.savechanges();  //the actual updating happens here

what tried implement same thing in mongodb (i trying use manual references since don't think dbrefs way go scenario (additional unwanted overload):

//user class public class user {     [bsonid]     public objectid id { get; set; }      [bsonelement("name")]     public string name { get; set; }      [bsonelement("posts")]     [bsonignoreifnull]     public list<post> plants { get; set; } }  // public class post {     [bsonid]     public objectid id { get; set; }      [bsonelement("body")]     public string body { get; set; }      [bsonelement("date_created")]     public datetime datecreated { get; set; }      [bsonelement("users_id")]     public user user { get; set; } }  //do other stuff should done

but of course, scheme not working , inserting document of type user example, causes creation of wired objects , documents (obviously)

so ultimate question this: how can achieve same functionality had in entity framework in mongodb using manual references , in short able these 2 things:

  1. somehow select users , posts above (the include method) using filter , deserialize 1 user object
  2. get user's posts , post's user implemented in models entity framework uses

thanks in advance


Comments

Post a Comment

Popular posts from this blog

angular - Ionic slides - dynamically add slides before and after -

hi i'm using ngfor create set of 3 slides while starting in middle i'm guaranteed able slide left or right on start. when slide right can simple listen reachedend , push slide array i'm looping. but have problem adding slide beginning. if same above , use e.g. array.unshift() or spread add item beginning, view think it's on position 0 , snaps view new slide. the code below work animates slide change index 1. slide = [0,1,2] //example loop slidechanged(event) { if(this.slides.isbeginning()){ this.slide = [this.slide[0]-1, ...this.slide]; this.slides.update(); this.slides.slideto(1) } } <ion-slides [initialslide]="1" (ionslidedidchange)="slidechanged($event)"> <ion-slide *ngfor="let item of slide"> <h1>slide {{item}}</h1> </ion-slide> </ion-slides> any appreciated! you can using ionslidenextend , ionslideprevend events slides . please...
Read more

Add a dynamic header in angular 2 http provider -

i have http interceptor built via tutorial https://scotch.io/@kashyapmukkamala/using-http-interceptor-with-angular2 the problem need have dynamic header changes automatically once changes 'mode' in app. service able tell interceptor change header, or have interceptor pull header (which string)from service each request. able throwing away patch method, call http.patch('new header string') set header string. call in service controls 'mode' setting. wondering if there way interceptor pull recent value service each request or if can add method http provider via interceptor? i've tried call service in interceptor each request returns undefined. because creating new instance of service or copying value before service fired , loaded/changed data. i don't want pass header string every http provider call because defeats purpose of having interceptor, id able set once changes or have provider fetch service before makes request. tl;dr : need add autom...
Read more

minify - Minimizing css files -

i want know how css files can minimized. currently, using external sites css minifier compress css files. however, after removing whitespaces, comments, etc, file sizes reduced 10-15%. how frameworks bootstrap manage make minimized versions kilobytes. as example, css is: body { background-color: #ff0; } the reduction goes 28 bytes 22 bytes other css files have lot more characters still smaller this. actually minifying code means it's remove thing code white space characters new line characters comments block delimiters it reduces amount of code has transferred on web , speed site load fastly.but unreadable format.
Read more