Couchbase Lite is an embedded NoSQL database for mobile devices that runs locally on the device with full CRUD and query capabilities. In this article, we discover how to integrate Couchbase Lite with Android Studio.
Android for mobile devices currently comes with an inbuilt local database—SQLite. This is an RDBMS based lightweight database that is available by default on all Android operating systems and provides CRUD operations to efficiently power your apps. SQLite is really a great choice when the requirement is just to have a simple database for your app to manage structured data. However, when the need is to store semi-structured or unstructured data and also to handle complex queries at scale without worrying about the schema of tables, then SQLite may not suit all of the developer’s requirements. A NoSQL database can be a better fit with these scaling requirements. Comparisons between an SQL and a NoSQL database have fuelled many debates, but both complement each other rather than compete with each other.
In this article, we start by discussing the general database requirements for mobile devices, followed by NoSQL’s prominence in today’s mobile world and, finally, look at integrating a NoSQL database called Couchbase Lite with Android Studio.
Databases for mobile devices
Deciding on a database for mobile devices requires us to consider various factors like memory constraints, the user experience, a lightweight UI, etc – parameters that are very different compared to what would be required for a desktop or Web environment. So before we jump into integrating Couchbase Lite with Android, let us first check out the various requirements for databases in the mobile environment, which are listed below.
- Unlike desktops or servers, mobile devices tend to have a lower battery life and relatively slower CPUs. Databases should hence not be performance intensive and should be able to effectively perform frequent operations like searches and updates.
- Mobile databases should have a smaller memory footprint. In certain ways, higher memory requirements would also lead to increased CPU cycles, where the kernel tries to intensively search for available memory space in the RAM. Lower footprint demands not only lead to lower CPU cycles but also ensure other mobile apps don’t get impacted.
- All the winning mobile apps are high performance with a fast loading time. Apps that freeze constantly are always on the backbench. Data consistency is another requirement when talking about these local databases on the mobile. If one were to go with a distributed database, the data may become inconsistent with respect to its remote counterpart if not taken care of, and the device might even discover this only on connecting to the Internet.
A mobile developer with a cloud based database backend, like say Firebase, needn’t worry about most of these constraints and requirements, but needs to include these factors in the equation when opting for a local database.
NoSQL’s relevance in the mobile world
With the increased usage of mobile devices, a tremendous amount of data is being generated these days. This fact, clubbed with technology proliferation into new spaces like mobility, IoT and analytics, has led to a demand for mobile devices and apps to handle this high volume of data at a high speed. Besides, the nature of data (especially when it comes from IoT devices for which data exchange is in real-time) is continuous and either semi-structured or the application needs to cater or adapt to various schemas. Some of the fundamental philosophies that NoSQL brings in address these challenges in the mobile space, as discussed below.
- The very fact that NoSQL is schema-less will help developers handle the data that lacks schema or structure. Besides, this property will also let them scale to changing or evolving requirements of data. The change in schema or structure could be done with ease at any point in time, in an independent way, without affecting the existing code. All of this will directly result in the agile delivery of apps, a quick turnaround time to market as against the time consuming process of design considerations, and limited scope for scalability and modularity in code when using a relational database.
- The distributed architecture of NoSQL databases ensures that they perform better than RDBMS. Besides, NoSQL doesn’t have complex join operations and normalised data nor does it include complex queries. These factors give it the upper hand when it comes to database performance. Effective performance directly results in the better user experience of mobile apps because of the reduced load time of UI components and activities. This directly improves the battery life too.
- Security is another aspect that should never be ignored while trying to achieve all these goals. The databases should be able to communicate to the server over secure channels. Besides, the channels that communicate with mobile devices over the Internet demand low latency for an improved mobile user experience. Also,exchange of data on the network should be lightweight to meet these performance requirements.
All that said, we still may not be able to eliminate SQL databases which complement NoSQL in many ways. NoSQL doesn’t guarantee atomicity or integrity of data which an RDBMS is capable of. So, it is the developer’s needs at the end of day that decide which database to go with.
Integrating Couchbase Lite with Android Studio
Couchbase Lite is an open source project available under Apache License 2.0. It is an embedded JSON database that can work as a standalone, in a P2P network, or as a remote endpoint for a Sync Gateway. In this article, we explain how to power your Android apps with Couchbase Lite.
Before getting onto integration, let us check out a few key features about this database.
- Couchbase Lite stores and manages all the data locally on your mobile device in a lightweight JSON format.
- Considering the requirements for a mobile database, Couchbase Lite qualifies with its lower memory footprint, built-in security with user authentication, AES based data based encryption, and transport to the server through TLS.
- Couchbase Lite provides CRUD and query support through native APIs, and also works well with existing REST architectures with its programmatic access through REST API.
- Stream and batch APIs from Couchbase Lite enable the transfer of real-time data in batches with low network latency and throughput, thereby addressing the exact demands of mobile apps.
Let us now go through the steps of installing Couchbase Lite and the other basic operations to get started.
It is assumed that readers are already conversant with the Android Studio IDE for developing Android apps. Integrating Couchbase dB with Android is straightforward. You could start off by adding the dependency elements given below in your application’s build.gradle:
dependencies {
compile 'com.couchbase.lite:couchbase-lite-android:+'
}
In the Java part of the application, you would need the following basic set of packages to start with:
import com.couchbase.lite.*; import com.couchbase.lite.android.AndroidContext;
Now that you are all set to use CouchBase APIs in your Android app, I’d like to illustrate a sample code, used for creating a database, and do an insert, update and delete of a document in it as mentioned in (1), (2), (3) and (4), respectively.
// (1) Get the database or create it if it doesn’t already exist.
Manager manager = new Manager(new JavaContext(),Manager.DEFAULT_OPTIONS);
Database db = manager.getDatabase("couchdB");
// (2) Create a new document (a record) in the database.
Document doc = db.createDocument();
Map properties = new HashMap();
properties.put("firstName", "OSFY");
doc.putProperties(properties);
// (3) Update a document.
doc.update(new Document.DocumentUpdater() {
@Override
public boolean update(UnsavedRevision newRevision) {
Map properties = newRevision.getUserProperties();
properties.put("firstName", "Johnny");
newRevision.setUserProperties(properties);
return true;
}
});
// (4) Delete a document.
doc.delete();
