Android SQLite R-Tree - How to install module?

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?

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)

June 2017

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

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):

This worked for me, extract from Android.mk file. It is for spatialite, sqlite spatial extension.

include $(CLEAR_VARS)
# -DOMIT_GEOS=0
# ./configure --build=x86_64-pc-linux-gnu --host=arm-linux-eabi
LOCAL_MODULE    := spatialite
LOCAL_CFLAGS    := -D__ANDROID__ -Dfdatasync=fsync -DOMIT_GEOCALLBACKS -DSQLITE_ENABLE_RTREE
LOCAL_LDLIBS    := -llog 
LOCAL_C_INCLUDES := \
    libiconv-1.13.1/include \
    libiconv-1.13.1/libcharset/include \
    geos-3.2.2/source/headers \
    geos-3.2.2/capi \
    proj-4.6.1/src
LOCAL_SRC_FILES := \
    ./libspatialite-amalgamation-2.4.0/spatialite.c \
    ./libspatialite-amalgamation-2.4.0/empty.cpp \
    ./libspatialite-amalgamation-2.4.0/sqlite3.c
LOCAL_STATIC_LIBRARIES := iconv proj geos
include $(BUILD_STATIC_LIBRARY)

https://www.sqlite.org/android/doc/trunk/www/index.wiki gives exactly the answer to your question and contains a step-by-step guide to install SQLite for your application with NDK/JNI.

Note that you have to add LOCAL_CFLAGS += -DSQLITE_ENABLE_RTREE in the jni/sqlite/Android.mk file as suggested by the documentation to compile with R-Tree Module enabled.

Don't forget to update your imports or the default SQLite database will be used.

来源：https://stackoverflow.com/questions/6132442/android-sqlite-r-tree-how-to-install-module

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android

sqlite

android-ndk

r-tree