How To search by non primary key in database allocated in backand.com?

al salam alykom ,
i need to get one item from database that allocated in backand.com web service but i want to
get this item based on non-primary key
example : i want to check if the username and password that the user enter is valid or not
so my sequence will be ,

  1. get the user row from database
  2. cehck if the user name is valid and also password

how to do thing like this , is there anther way to do thing like this ?

thank in advance

How are you accessing “backand.com” in your Ionic 2 app? This sounds like a problem for their library.

it’s the easy part of the game
by using http requests you can do this
example
first you must have this in your code

  auth_token: {header_name: string, header_value: string} = {header_name: 'AnonymousToken', header_value: 'YourAnonymousToken '};
  api_url: string = 'https://api.backand.com';

you can easily get your AnonymousToken by enter to your app and then security&auth and then Configuration and then mark Anonymous Access and then copy your token

to use http requests
first you must import the http from angular 1
import { Http } from '@angular/http';
second using http

public getTodos() {
    return this.http.get(this.api_url + '/1/objects/todos?returnObject=true', {
      headers: this.authHeader()
    })
    .map(res => res.json())
  }

in backand webstie you can know any request from
your Aspp >> Objects >> your database table >> rest api tab >> then thing like this wil be appear


by expand any of this you will be able to test any thing you want and you will get responding address for http request