Android SQLite R-Tree - How to install module?

Question

http://www.sqlite.org/rtree.html says that the r*tree is "included as part of the amalgamation but is disabled by default" and to enable it "simply compile with the SQLITE_ENABLE_RTREE C-preprocessor macro defined"

Well I want to use R-trees in my android app, but clearly SQLite is all pre-installed etc. Is there a way to enable it on a user's phone/device?

Alternatively, is it possible to use the NDK and the freely available source code for SQLite?

Answer 1

June 2017

1. Go to the: download page and grab sqlite-android-xxxxx.aar
2. Rename it to .aar instead of .zip
3. Create a simple project with Android Studio (no need for C++ support)
4. In the project tree right click app / new / Module select Import .JAR/.AAR Package
5. Select the renamed file, click finish
6. In Android Studio go to menu: File / Project structure. Click app (under Modules), select the Dependencies Tab, Add module dependency SQLite-android-xxxxx
7. Before using any SQLite functions, call: System.loadLibrary("sqliteX");
8. Replace SQlite imports to org.sqlite.database.sqlite.xxxxxx

9. In onCreate you can make a quick test with a memory database:

   System.loadLibrary("sqliteX");
   
   // get the SQLite version
   String query = "select sqlite_version() AS sqlite_version";
   SQLiteDatabase db = SQLiteDatabase.openOrCreateDatabase(":memory:", null);
   Cursor cursor = db.rawQuery(query, null);
   String sqliteVersion = "";
   if (cursor.moveToNext()) {
       sqliteVersion = cursor.getString(0);
   }
   
   // do some R*Tree things (this will fail for the standard SQLite)
   db.execSQL("CREATE VIRTUAL TABLE demo_index USING rtree(id, minX, maxX, minY, maxY);");
   db.execSQL("INSERT INTO demo_index VALUES(1,-80.7749, -80.7747, 35.3776, 35.3778);");
   db.execSQL("INSERT INTO demo_index VALUES(2,-81.0, -79.6, 35.0, 36.2);");
   
   cursor = db.rawQuery("SELECT id FROM demo_index WHERE minX>=-81.08 AND maxX<=-80.58 AND minY>=35.00  AND maxY<=35.44;", null);
   
   int id = -1;
   if (cursor.moveToFirst()) {
       do {
           id = cursor.getInt(0);
       } while (cursor.moveToNext());
   }
   db.close();
   

The links (for all of the above):

• SQLite Android Bindings
• Installation
• Very Simple App
• Application Programming
• The SQLite R*Tree Module

Answer 2

You can absolutely compile your own version of SQLite. We do this in order to enable the encryption/codec modules from wxSQLite. Take a look at the SQLite source in the Android Git repository. Basically it's as easy and creating a Android.mk with the options (such as SQLITE_ENABLE_RTREE) you'd like enabled. Of course, this will give you a native library. In order to use it you'll need to access it from the NDK or create a wrapper (again, you can look at the Android repository and Java/JNI wrappers to SQLite)