initializeApp() {
    this.platform.ready().then(() => {
      StatusBar.styleDefault();
      if (window.cordova) {
        this.createDatabase();
      }
    });
  }

private createDatabase(): void {
    let db: SQLite = new SQLite();
    db.openDatabase({
      name: "data.db",
      location: "default"
    }).then(() => {
      db.executeSql("CREATE TABLE IF NOT EXISTS chats (_id TEXT PRIMARY KEY, memberIds TEXT, title TEXT, subTitle TEXT, picture TEXT, lastMessageId TEXT, lastMessageCreatedAt DATE)", {}).then((chatData) => {
        console.log("chats TABLE CREATED: ", chatData);
        db.executeSql("CREATE TABLE IF NOT EXISTS messages (_id TEXT PRIMARY KEY, chatId TEXT, senderId TEXT, ownership TEXT, content TEXT, createdAt DATE, changeDate BOOLEAN, readByReceiver BOOLEAN)", {}).then((messageData) => {
          console.log("messages TABLE CREATED: ", messageData);
        }, (error) => {
          console.error("Unable to execute messages sql", error);
        });

      }, (error) => {
        console.error("Unable to execute chats sql", error);
      });
    }, (error) => {
      console.error("Unable to open database", error);
    });
  }

constructor() {
    if (window.cordova) {
        this.openDatabase();
    }
}

private openDatabase(): void {
    console.log('openDatabase');
    this.database.openDatabase({ name: "data.db", location: "default" }).then(() => {
        this.refreshChats();
        this.refreshMessages();
    }, (error) => {
        console.log("ERROR: ", error);
    });
}