[CLOSED] Can't get user from SQLite database

Ionic Framework ionic-v3
1

Hi, I’m new to Ionic and I’m starting to develop an app, and for now I just need to implement a provisory register/login using SQLite.

The problem is that I am not able to log in after registering a user, because it seems that the .get (email: string) function in UsuarioProvider is not returning the Usuario object. My only return is the “User not found” toast.

I would appreciate if someone could indicate possible causes, since I do not have much experience with the framework

usuarios.ts


import { Injectable } from '@angular/core';
import { SQLiteObject } from '@ionic-native/sqlite';
import { DatabaseProvider } from '../database/database';

@Injectable()
export class UsuariosProvider {

  constructor(private dbProvider: DatabaseProvider) { }

  public insert(usuario: Usuario) {
    return this.dbProvider.getDB()
      .then((db: SQLiteObject) => {
        let sql = 'insert into usuarios (nome, email, senha) values (?, ?, ?)';
        let data = [usuario.nome, usuario.email, usuario.senha];

        return db.executeSql(sql, data)
          .catch((e) => console.error(e));
      })
      .catch((e) => console.error(e));
  }

  public update(usuario: Usuario) {
    return this.dbProvider.getDB()
      .then((db: SQLiteObject) => {
        let sql = 'update usuarios set nome = ?, email = ?, senha = ? where id = ?';
        let data = [usuario.nome, usuario.email, usuario.senha, usuario.id];

        return db.executeSql(sql, data)
          .catch((e) => console.error(e));
      })
      .catch((e) => console.error(e));
  }

  public remove(id: number) {
    return this.dbProvider.getDB()
      .then((db: SQLiteObject) => {
        let sql = 'delete from usuarios where id = ?';
        let data = [id];

        return db.executeSql(sql, data)
          .catch((e) => console.error(e));
      })
      .catch((e) => console.error(e));
  }

  public get(email: string) {
    return this.dbProvider.getDB()
      .then((db: SQLiteObject) => {
        let sql = 'select * from usuarios where email = ?';
        let data = [email];

        return db.executeSql(sql, data)
          .then((data: any) => {
            if (data.rows.length > 0) {
              let item = data.rows.item(0);
              let usuario = new Usuario();
              usuario.id = item.id;
              usuario.nome = item.nome;
              usuario.senha = item.senha;
              usuario.email = item.email;
             
              return usuario;
            }

            return null;
          })
          .catch((e) => console.error(e));
      })
      .catch((e) => console.error(e));
  }

}

export class Usuario {
  id: number;
  nome: string;
  email: string;
  senha: string;
}

database.ts

import { Injectable } from '@angular/core';
import { SQLite, SQLiteObject } from '@ionic-native/sqlite';

@Injectable()
export class DatabaseProvider {

  constructor(private sqlite: SQLite) { }

  public getDB() {
    return this.sqlite.create({
      name: 'database.db',
      location: 'default'
    });
  }

  public createDatabase() {
    return this.getDB()
      .then((db: SQLiteObject) => {

      
        this.createTables(db);

      })
      .catch(e => console.log(e));
  }

  private createTables(db: SQLiteObject) {
    
    db.sqlBatch([
      ['CREATE TABLE IF NOT EXISTS usuarios (id integer primary key AUTOINCREMENT NOT NULL, nome TEXT, email TEXT, senha TEXT)'],
      ['CREATE TABLE IF NOT EXISTS atividades (id integer primary key AUTOINCREMENT NOT NULL, titulo TEXT, data DATE, hora TEXT']
    ])
      .then(() => console.log('Tables created'))
      .catch(e => console.error('Error creating tables', e));
  }
}

login.ts

import { Component } from '@angular/core';
import { NavController, ToastController } from 'ionic-angular';
import { CadastroPage } from '../cadastro/cadastro';
import { PrincipalPage } from '../principal/principal';
import { UsuariosProvider, Usuario } from '../../providers/usuarios/usuarios'

@Component({
  selector: 'page-login',
  templateUrl: 'login.html'
})
export class LoginPage {

  usuario: Usuario;
  constructor(public navCtrl: NavController, private toast: 
   ToastController, private usuarioProvider: UsuariosProvider) {
    this.usuario = new Usuario();
    
  }
    

    private login() {
    this.usuarioProvider.get(this.usuario.email)
      .then((result: Usuario) => {
       
        if (this.usuario.senha==result.senha && this.usuario.senha!="") {
            this.goToPrincipal();
            
        } else {
            this.toast.create({ message: 'Wrong password! Try again', duration: 3000, position: 'bottom' }).present();
            }
         
      })
      .catch(() => {
        this.toast.create({ message: 'User not found!', duration: 3000, position: 'bottom' }).present();  
    })
  }


    
    public goToPrincipal(){
        this.navCtrl.setRoot(PrincipalPage);
    }
    
    public goToCadastro(){
        this.navCtrl.push(CadastroPage);
    }
    
}

login.html

<ion-content padding>

    <div text-center>

        <img margin-top="5%" src="assets/imgs/logo-placeholder.png">
        <br>

        <button class="btnLoginGoogle">  <ion-icon name="logo-google" size=large margin-right=auto></ion-icon>
FAZER LOGIN COM O GOOGLE </button>

        <ion-label class="labelLogin"> OU </ion-label>
        <ion-list>
            <ion-item>
                <ion-input [(ngModel)]="usuario.email" margin-top="15px" class="txtFieldLogin" type="email" placeholder="E-mail"></ion-input>
            </ion-item>
            <ion-item>
                <ion-input [(ngModel)]="usuario.senha" class="txtFieldLogin" type="password" placeholder="Senha">
                </ion-input>
            </ion-item>
            <ion-label [hidden]="true"></ion-label>
        </ion-list>
        <button (click)="login()" class="btnEntrar">ENTRAR</button>

        <button (click)="goToCadastro();" class="btnCadastrar"> AINDA NÃO POSSUI UMA CONTA?</button>
    </div>
</ion-content>