Besides Java, what do you need for Android?

Question

Java

Hello friends!
I already understood that for Android you need to know Java. Well, ok, what about the relationship with databases? It's SQL, right? And interaction with SQL? In general, I don’t really understand, but where will this SQL be located?
So I want to stir up an application with maps, chat, and so on. Should it be stored somewhere - correspondence, pictures, etc.? Where is this stored? Where is it physically located? Ordinary hosting or what.
Do I understand correctly that Java alone is indispensable when writing an application for android? Or is it 90%, let's say, of everything that is needed?
Thanks

Answer 1

Roughly speaking, you need to know the Android framework, which uses java as its programming language.
Android uses SQLite or NoSQL solutions.
In fact, you open off the dock and read.
Here Google can teach you where to start https://developer.android.com/training/index.html

Answer 2

I want to program for android. Question #1 - java-help.ru/i-want-to-develop-android-apps-1
I want to program for Android. Question #2 - java-help.ru/i-want-to-develop-android-apps-2
I want to program for Android. Question #3 - java-help.ru/i-want-to-develop-android-apps-3
I want to program for Android. Question #4 - java-help.ru/i-want-to-develop-android-apps-4
I want to program for Android. Question #5 - java-help.ru/i-want-to-develop-android-apps-5

Answer 3

the main components of android sdk ─ activity, fragment, servise, reciver ... must have
Knowledge of the main components in the same place
Development skill ui ─ layout xml layout, a general understanding of the work of resources
Database ─ helpers, providers, loaders Networking
skills (here from the team it’s different to the team, but you can’t understand that you can’t put your fingers in the socket, that is, you can’t send requests from the ui stream))), well, common sense is natural ─ to understand what rest is and how best to organize work with it)
this is a certain minimum of android development. And the rest are all areas of software development that you understand as needed. It is clear that with knowledge of the syntax of one language you will not go far.

Answer 4

Where is this stored?

It can be stored on the device itself (internal memory or SD card), then SQLite is used - a local, or rather embedded database, interaction directly through android.sqliteeither ORM, but if you need access from other application instances, then you need a server, with any database and regular REST (HTTP) API, it is possible on hosting, it is possible on VPS/VDS, as well as with websites.
Java is just syntax and nothing else, you need to learn how to work with SDKs and libraries, such as those mentioned android.sqliteand ORM, and in the case of a server, you need a library for REST API (HTTP requests), again there is a built-in Android, and there are third-party high-level ones, Retrofit for example, or you can write your own, you also need to study the UI very well, it is very abstract on mobile devices, therefore it is quite complicated.