Android SQLite R-Tree - How to install module?

问题

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?

回答1:

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)

回答2:

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):

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

回答3:

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)

回答4:

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

标签

android

sqlite

android-ndk

r-tree