I would like to create a database in cache so it could be wiped out when user clicks Clear cache button.
In SQLiteOpenHelper constructor there is only argument to pass a name of database, not a directory (default is dadabases).
Is there any option to delete such DB when user wants to clear cache?
Here is an example of creating a database in your cache directory:
public class CachedDatabase extends SQLiteOpenHelper {
public CachedDatabase(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) {
super(context, new File(context.getCacheDir(), name).getAbsolutePath(), factory, version);
}
@Override public void onCreate(SQLiteDatabase db) {
// just for testing
db.execSQL("CREATE TABLE example (id INTEGER PRIMARY KEY AUTOINCREMENT, foo, bar, baz, qux)");
}
@Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
}
All you need to do is pass the absolute path as the name parameter in the constructor.
Tested just to make sure it was created in /data/data/[package_name]/cache:
CachedDatabase cachedDatabase = new CachedDatabase(this, "TEST", null, 1);
SQLiteDatabase database = cachedDatabase.getWritableDatabase();
ContentValues values = new ContentValues();
values.put("foo", "foo");
values.put("bar", "bar");
values.put("baz", 123);
values.put("qux", true);
database.insert("example", null, values);
Checking for the database:
$ adb shell
$ run-as [YOUR_PACKAGE_NAME]
$ ls cache
TEST
TEST-journal
You can create and open a database in a specific location, but you need to use SQLiteDatabase class (choose one of the openOrCreateDatabase methods): as you mentioned you can't create a database in a different path using the provided SQLiteOpenHelper.
You can also modify the code of the SQLiteOpenHelper to match your needs. Take the source code from the link, copy in a new class of your project and modify the getDatabaseLocked method.
You can also take inspiration from SQLiteAssetHelper.
If you are looking to clear the data in tabledb.execSQL("delete * from "+ TABLE_NAME);
you can also delete the tables db.delete("TABLE_NAME", null, null);
