myhomie_app/lib/Helpers/DatabaseHelper.dart

import 'dart:convert';

import 'package:myhomie_app/Models/homieContext.dart';
import 'package:path/path.dart';
import 'package:sqflite/sqflite.dart';

class DatabaseHelper {
  static final _databaseName = "homie_database.db";
  static final _databaseVersion = 1;

  static final table = 'homieAppContext';

  static final columnId = 'id';
  static final columnUserId = 'deviceId';
  static final columnHomeId = 'homeId';
  static final columnToken = 'token';
  static final columnHost = 'host';
  static final columnLanguage = 'language';

  DatabaseHelper._privateConstructor();
  static final DatabaseHelper instance = DatabaseHelper._privateConstructor();

  static Database _database;
  Future<Database> get database async {
    if (_database != null) return _database;
    _database = await _initDatabase();
    return _database;
  }

  _initDatabase() async {
    String path = join(await getDatabasesPath(), _databaseName);
    return await openDatabase(path,
        version: _databaseVersion, onCreate: _onCreate);
  }

  // SQL code to create the database table
  Future _onCreate(Database db, int version) async {
    await db.execute('''
          CREATE TABLE $table (
            $columnId TEXT NOT NULL PRIMARY KEY,
            $columnUserId TEXT NOT NULL,
            $columnToken TEXT NOT NULL,
            $columnHomeId TEXT NOT NULL,
            $columnHost TEXT NOT NULL,
            $columnLanguage TEXT NOT NULL     
          )
          ''');
  }

  Future<int> insert(HomieAppContext tabletAppContext) async {
    Database db = await instance.database;

    var res = await db.insert(table, tabletAppContext.toMap());
    return res;
  }

  Future<void> update(HomieAppContext tabletAppContext) async {
    // Get a reference to the database.
    final db = await instance.database;

    await db.update(
      'tabletAppContext',
      tabletAppContext.toMap(),
      where: "id = ?",
      whereArgs: [tabletAppContext.id],
    );
  }

  Future<List<Map<String, dynamic>>> queryAllRows() async {
    Database db = await instance.database;
    var res = await db.query(table, orderBy: "$columnId DESC");
    return res;
  }

  Future<int> delete(String email) async {
    Database db = await instance.database;
    return await db.delete(table, where: '$columnId = ?', whereArgs: [email]);
  }

  Future<void> clearTable() async {
    Database db = await instance.database;
    return await db.rawQuery("DELETE FROM $table");
  }

  Future<HomieAppContext> getData() async {
    HomieAppContext homieAppContext;

    await DatabaseHelper.instance.queryAllRows().then((value) {
      value.forEach((element) {
        print("DB - CONTEXT --- ");

        homieAppContext = HomieAppContext(
            id: element["id"],
            userId: element["userId"],
            token: element["token"],
            host: element["host"],
            homeId: element["homeId"],
            language: element["language"]
        );
      });
    }).catchError((error) {
      print(error);
    });

    return homieAppContext;
  }
}