Develop Reference

Switching from SQLite to Firebase?

So for my Android App which stores data of workouts I have been using a SQLite Database so far. Now I want to implement these features:
Offer workouts in real time (with Firebase Database)
Being able to access your data on other devices and maybe from an web app
later
I figured, that for this purpose Firebase would be a great fit. But switching from SQLite to Firebase would bring a few down sights in my opinion:
Every user would need to sign up. I think for some users this is a reason to
not use my app. There is no way to avoid having to sign up when using
Firebase to store the data for user, right?
I´m not sure how good the offline options of Firebase Database is. How long
will the data be accessible without a connection? Is the capacity and
performance comparable to a SQLite Database?
I thought an alternative way could be to use Firebase just for offering the workouts but keep the data about a workout (repetitions, weight, ...) in a SQLite Database. Then I could upload the Database File with Firebase and another Device could download and continue it. Could that be an option?
Any thoughts and advice are appreciated!

Every user would need to sign up. I think for some users this is a
reason to not use my app. There is no way to avoid having to sign up
when using Firebase to store the data for user, right?
Right. (Technically it is possible, however you will need to enable read / write operations to non registered uses which is a no-no and not recommended at all.)
I´m not sure how good the offline options of Firebase Database is. How
long will the data be accessible without a connection? Is the capacity
and performance comparable to a SQLite Database?
From the firebase database docs: Firebase apps automatically handle temporary network interruptions. Cached data is available while offline and Firebase resends any writes when network connectivity is restored..
So yes, you can continue writing to it even when offline and read the already cached data, but this does not solve your concern that users will have to register to use the app.
Possible solution
Use both SQLite and Firebase database:
For a registered user, always write in both SQLite and Firebase to keep them in sync (write in Firebase first and then SQLite). Another option is to write in SQLite and sync to Firebase every X minutes. Read data from Firebase when online and from SQLite when offline.
When the user is offline, you will to write data to SQLite. You will need to mark those records as non-synced so that next time it is connected you will write them to firebase.
Also, when reconnected, you'll need to somehow merge firebase data (that might have changed) and local SQLite data. The algorithm for this depends on your app.
For non-registered users, use SQLite only.
The downside to all this is that the complexity of your application increases a lot. It's up to you to decide whether it's worth it or not. :)

User Sign up and retrieval of all user data app in android with SQLite

I am a newbie in Android Development, I want to build an app where user from anywhere can register (Userdata should be save in sqlite db) and after registration n login process user can see all the other user list who are register.
Is this possible using android and sqlite db. I search many times on google but all i found tutorial for sqlite. I started to follow the tutorial but i am confuse as it is stated that Sqlite can only save APP data and private data of user. How could i make app for register user from anywhere. Suggestion and links for another method to do that is also helpful, Please Help
Thanks in Advance

SQLite can save only data for specific user in the specific device of the user. No one can access SQLite database which is stored in my device from any other device. Such scenario can be implemented by centralized system where all the details are stored in Mysql, mongo DB or similar. These databases are stored in centralized system so that it can be accessed from anywhere by anyone as per authorization settings. It is accessed by the internet.
So as per your requirement go for centralized system where database can be used by using web services. Web services can interact with server in which database is stored and can give you desired output in form of JSON or XML.

How to sync data between different devices

I am planing to implement an app and I have come to a point where I don't know what is the best approach.
Scenario:
I have an app where I am making a todo list and I am adding 3 items. I use my phone for this.
Then I take my tablet and want to continue adding another task. Then after a while I take my wife's phone and want to add 2 new tasks.
Basically I want to have a very simple way of storing the tasks online and be able to sync it with the app.
I am seeing two possible ways:
have a web server with a database + web service calls. This has the disadvantage of having a host paid, learn some extra mysql + web service techniques.
store somehow the data on cloud and allow the app by login to access an account which stores the file. I am thinking here at something like Google Drive / Dropbox. But I don't know how I would be able to sync only the updated values, not the whole file. Because I am thinking, if I store all the tasks into one file, each time I update the file, I'll need to upload it fully, which is not the best approach.
I am open to any advices. What approach would you recommend ?

There's also Google Drive's "Application Data" folder.
https://developers.google.com/drive/android/appfolder
This has the advantage of using the user's storage space.

I would look into either Google App Engine or Amazon Web Services. They both give you free allotment of usage per month and if you go over then you start paying, chances are you wont get past the free tier for a while.
AWS is a bit more mature than GAE currently and seemed to be a bit easier to implement that GAE was when I was researching them

Take a look at the new training class for sync adapters:
http://developer.android.com/training/sync-adapters/index.html for the basics of sending data from your device to a server.
On the Android device, I suggest you store your tasks in a content provider. This helps you keep track of updates since the last time you synced. You can then query the provider during your sync, send only the data that's been updated, and store the data on the server.
You should probably store the last update time on the device, so you can tell if the server contains data that isn't yet on the device. Remember that you'll have to download tasks as well if you want all devices to be in sync.

You can try Google's Firebase. Firebase provides SDK for Android and iOS devices. And also, firebase supports offline and syncing. Firebase also provides object storage service. It easier to create firebase app than you think. Have look at this firebase's firestore service.

You can take a look at our Rethync framework (freeware with source) . Using it you can simplify the task of detecting modifications and sync only updated data. Next, Rethync provides both client- and server-side API so you can create your own service (and host it on the web side) or you can write your own transport for the cloud service of your choice (we will provide some transports in future, they are under development now).

How to sync android database with web database?

Hi I want to sync android database with web database, my scenario is:
I want to make an android app dictionary. The dictionary words are added by web forms and the user android consume those words. In the Android application I have the historical of words that the user displayed and data of their studies, that should be synchronized online in case of change user phone or him have multiple devices.
My question is how to do that:
I need authentication or can get the User's google account to identify him?
How should I synchronize these two databases?
If I use Backup API i can get the same data in diferents devices?

I need authentication or can get the User's google account to identify him? That's your decision. You could even provide both methods. Some people don't want to share everything with Google, others don't care. If you want to create your own authenticator read the Udinic blog post about it.
How should I synchronize these two databases? You need a sync adapter in Android and a receiving service in your web application. In the Udinic blog there is also a tutorial about sync adapters. On server side you could create a REST service for example.
If I use Backup API i can get the same data in differents devices? The Backup API doesn't seem to be the right choice as it only restores data during the initial setup and I assume you want to synchronize the data all the time.

Network Accessibility and Content Providers on android

I recently have gotten very interested in android development. I have this application that needs to be able to store user accounts onto a database. How do I go about making this database network accessible, so users of my application can access their account? I've been looking into this and I think that content providers are one method of solving this problem. However, I don't know anything about content providers so some clarification would be great. Anyways here are my questions straightforward:
How do I go about making a database network accessible so users of my android application can access their account?
What is a content provider and are they free?
Thanks for your time and I appreciate the help.

Good questions, but too broad and open-ended. Also, I find it hard to understand
You have an application that needs to be able to store user accounts onto a database. Where will the database be, on the web or on the device? Do you want to be able to access a web database from the device? Do you intend to store the user accounts on the device?
If you have a web-based database, you have to provide a web server to get data from the database and offer it to your Android app. There are many ways to do this.
A content provider is one of the four main building blocks of an Android app (the others being activity, service, and broadcast receiver). Content providers provide a standard interface between local data and other components, including components in other apps. A content provider can handle files, databases, and even internal data structures you build within the provider, but most content providers encapsulate an SQLite database.
In regard to transferring data between a server and the device, content providers often represent the location of the local data. Content providers don't automatically transfer data, but in conjunction with other parts of Android a content provider simplifies the process of detecting when data has changed.
To transfer data between the device and a server, you'll need to set up your server to provide database data using HTTP, learn how to connect to the HTTP server interface from Android, send requests (I suggest the REST protocol) to access the server, send REST requests to transfer data, and then store the data on the device, probably by using a content provider.
You may also need to learn how to work with user accounts in Android, using the android.accounts.Account class.
Most of these topics are described in detail at the website developer.android.com, which is Google's official Android SDK documentation.