In my project, i used like this
public class DatabaseHelper extends SQLiteOpenHelper {
private final static String TAG = DatabaseHelper.class.getSimpleName();
private static DatabaseHelper sInstance;
private Context mContext;
private static final String DATABASE_NAME = "xxxx";
private static final String DATABASE_NAME_OLD = "xxxx_old";
private static final int DATABASE_VERSION = 12;
private String pathToSaveDBFile, absolutepathToSaveDBFile;
private SQLiteDatabase db;
private Cursor cursor;
public static synchronized DatabaseHelper getInstance(Context mContext) {
if (sInstance == null) {
sInstance = new DatabaseHelper(mContext);
}
return sInstance;
}
/**
* initialization constructor
*
* @param context
*/
private DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
this.mContext = context;
pathToSaveDBFile = new StringBuffer(context.getFilesDir().getAbsolutePath()).append("/").append(DATABASE_NAME).toString();
absolutepathToSaveDBFile = new StringBuffer(context.getFilesDir().getAbsolutePath()).append("/").append(DATABASE_NAME_OLD).toString();
}
/**
* prepare database related process
*
* @throws IOException
*/
public void prepareDatabase() throws IOException {
//boolean dbExist = checkDataBase();
if (checkDataBase()) {
Log.d(TAG, "Database exists.");
// int currentDBVersion = getVersionId();
if (DATABASE_VERSION > getVersionId()) {
Log.d(TAG, "Database version is higher than old.");
if (renameDatabase()) {
Log.d(TAG, "renameDatabase() ");
try {
if (copyDataBase()) {
deleteDb();
setVersionId(DATABASE_VERSION);
}
} catch (Exception e) {
Log.e(TAG, e.getMessage());
}
}
}
} else {
try {
/// copy db
copyDataBase();
} catch (Exception e) {
Log.e(TAG, e.getMessage());
}
}
}
/**
* db exist or not?
*
* @return db checked status
*/
private boolean checkDataBase() {
Log.d(TAG, "checkDataBase()");
boolean checkDB = false;
try {
File file = new File(pathToSaveDBFile);
checkDB = file.exists();
} catch (SQLiteException e) {
Log.d(TAG, e.getMessage());
}
Log.d(TAG, "checkDataBase: " + checkDB);
return checkDB;
}
/**
* db copying
*
* @return db copy status
*/
private Boolean copyDataBase() {
try {
Log.d(TAG, "copyDataBase()");
OutputStream os = new FileOutputStream(pathToSaveDBFile);
InputStream is = mContext.getAssets().open("db/" + DATABASE_NAME);
byte[] buffer = new byte[1024];
int length;
while ((length = is.read(buffer)) > 0) {
os.write(buffer, 0, length);
}
is.close();
os.flush();
os.close();
return true;
} catch (IOException e) {
e.getMessage();
return false;
}
}
/**
* db renaming
*
* @return boolean status
*/
private boolean renameDatabase() {
try {
Log.d(TAG, "renameDatabase: ");
File from = new File(pathToSaveDBFile);
File to = new File(absolutepathToSaveDBFile);
if (from.renameTo(to)) {
return true;
}
return false;
} catch (Exception e) {
e.getMessage();
return false;
}
}
/**
*
*
* @return boolen status
*/
private boolean revertBack_to_OlderName() {
try {
Log.d(TAG, "renameDatabase: ");
File from = new File(absolutepathToSaveDBFile);
File to = new File(pathToSaveDBFile);
if (from.renameTo(to)) {
return true;
}
return false;
} catch (Exception e) {
e.getMessage();
return false;
}
}
/**
* db deletion
*
* delete db
*/
public void deleteDb() {
File file = new File(absolutepathToSaveDBFile);
if (file.exists()) {
file.delete();
Log.d(TAG, "Database deleted.");
}
}
@Override
public void onCreate(SQLiteDatabase sqLiteDatabase) {
}
@Override
public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {
}
@Override
public synchronized void close() {
db.close();
super.close();
}
/**
* get db version info
*
* @return version no
*/
private int getVersionId() {
try {
db = SQLiteDatabase.openDatabase(pathToSaveDBFile, null, SQLiteDatabase.OPEN_READONLY);
String query = "SELECT " + AS_DB_VERSION_NUMBER + " FROM " + AS_DB_VERSION_TABLE;
cursor = db.rawQuery(query, null);
cursor.moveToFirst();
int v = cursor.getInt(0);
cursor.close();
close();
return v;
} catch (SQLiteException e) {
e.getMessage();
return 0;
}
}
/**
* set db version no to
* @param version
*
* @return status
*/
private boolean setVersionId(int version) {
try {
db = SQLiteDatabase.openDatabase(pathToSaveDBFile, null, SQLiteDatabase.OPEN_READWRITE);
ContentValues values = new ContentValues();
values.put(AS_DB_VERSION_NUMBER, version);
db.update(AS_DB_VERSION_NUMBER, values, AS_DB_VERSION_ID + " = 1", null);
close();
return true;
} catch (SQLiteException e) {
e.getMessage();
return false;
}
}
}
you can use these code in your contest
