I'm using an external sqlite database rather than creating one in my android studio project since the database will have some already populated data in it. But I have to insert some more data as well.
And when I insert any new data, it shows the new data but as I close my android app and open again to see the data, the newly inserted data through the app are somehow deleted, only prepopulated data are shown.
I am using DB browser for sqlite to create the external sqlite database and pre-populate it with some data there. In my android studio project, I added this database into my assets folder and implemented SQLiteOpenHelper class to access this database. Reading the data from the database table is a success. Now as I insert new data I can read the new data temporarily as well. Temporarily in the sense that after i close my app the new data are lost.
the table of my external sqlite database:
CREATE TABLE `table_name` (
`Id` INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
`Content` TEXT NOT NULL
);
SQLiteOpenHelper class:
public class ProcessExternalDBHelper {
private static final String DATABASE_NAME = "database_name.db";
private static final int DATABASE_VERSION = 1;
private static String DATABASE_PATH = "";
private static final String DATABASE_TABLE = "table_name";
private static final String KEY_ROWID = "Id";
private static final String KEY_CONTENT = "Content";
private ExternalDbHelper ourHelper;
private final Context ourContext;
private SQLiteDatabase ourDatabase;
private static class ExternalDbHelper extends SQLiteOpenHelper {
public ExternalDbHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
if (Build.VERSION.SDK_INT >= 17) {
DATABASE_PATH = context.getApplicationInfo().dataDir +
"/databases/";
} else {
DATABASE_PATH = "/data/data/" + context.getPackageName() +
"/databases/";
}
}
#Override
public void onCreate(SQLiteDatabase db) {
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int
newVersion) {
}
}
public ProcessExternalDBHelper(Context context) {
ourContext = context;
}
//for reading
public ProcessExternalDBHelper openRead() throws SQLException {
ourHelper = new ExternalDbHelper(ourContext);
ourDatabase = ourHelper.getReadableDatabase();
return this;
}
//for writing
public ProcessExternalDBHelper openWrite() throws SQLException{
ourHelper = new ExternalDbHelper(ourContext);
ourDatabase = ourHelper.getWritableDatabase();
return this;
}
public void close() {
if (ourHelper != null) {
ourHelper.close();
}
}
//Create database in activity
public void createDatabase() throws IOException {
createDB();
}
//Create db if not exists
private void createDB() {
boolean dbExists = checkDatabase();
if (!dbExists) {
openRead();
try {
this.close();
copyDatabase();
} catch (IOException ie) {
throw new Error("Error copying database");
}
}
}
private boolean checkDatabase() {
boolean checkDB = false;
try {
String myPath = DATABASE_PATH + DATABASE_NAME;
File dbfile = new File(myPath);
checkDB = dbfile.exists();
} catch (SQLiteException e) {
}
return checkDB;
}
private void copyDatabase() throws IOException {
InputStream myInput = null;
OutputStream myOutput = null;
String outFileName = DATABASE_PATH + DATABASE_NAME;
try {
myInput = ourContext.getAssets().open(DATABASE_NAME);
myOutput = new FileOutputStream(outFileName);
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer)) > 0) {
myOutput.write(buffer, 0, length);
}
myOutput.flush();
myOutput.close();
myInput.close();
} catch (IOException ie) {
throw new Error("Copydatabase() error");
}
}
//To show all available contents in my database
public List<Model> findallContents() {
List<Model> mContents = new ArrayList<>();
String[] columns = new String[]{KEY_CONTENT};
Cursor cursor = ourDatabase.query(DATABASE_TABLE, columns, null, null,
null, null, null);
int iContent = cursor.getColumnIndex(KEY_CONTENT);
for (cursor.moveToFirst(); !cursor.isAfterLast(); cursor.moveToNext())
{
Model model= new Model();
model.setContent(cursor.getString(iContent));
mContents.add(model);
}
cursor.close();
return mContents;
}
public void addContent(String content) {
ContentValues contentValues = new ContentValues();
contentValues.put(KEY_CONTENT, content);
ourDatabase.insert(DATABASE_TABLE, null, contentValues);
ourDatabase.close();
}
}
My Model.java class:
public class Model {
private String mContent;
public String getContent() {
return mContent;
}
public void setContent(String content) {
this.mContent = content;
}
}
Finally my activity class where i read and write the data:
public class MainActivity extends AppCompatActivity {
private EditText editText_Content;
private ImageButton imageButton_Save;
private List<Model> mContentsArrayList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ProcessExternalDBHelper myDbHelper = new ProcessExternalDBHelper(this);
try {
myDbHelper.createDatabase();
} catch (IOException ioe) {
throw new Error("Unable to CREATE DATABASE");
} finally {
myDbHelper.close();
}
initialize();
GetContents();
imageButton_Save.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (!(editText_Content.getText().toString().trim().isEmpty()))
{
SaveContents();
}
}
});
}
private void initialize() {
editText_Content = findViewById(R.id.editText_contents);
imageButton_Save = findViewById(R.id.imageButton_save);
mContentsArrayList = new ArrayList<>();
}
//GetContents and show them later in my RecyclerView
private void GetContents() {
try {
mContentsArrayList.clear();
ProcessExternalDBHelper autoProcess = new
ProcessExternalDBHelper(this);
autoProcess.openRead();
mContentsArrayList.addAll(autoProcess.findallContents();
autoProcess.close();
} catch (Exception e) {
}
}
//For saving content into database
private void SaveContents() {
String content = editText_Content.getText().toString();
try {
ProcessExternalDBHelper autoProcess = new
ProcessExternalDBHelper(this);
autoProcess.openWrite(); //for writing into database
autoProcess.addContent(content);
autoProcess.close();
editText_Content.getText().clear();
} catch (Exception e) {
}
}
}
Finally I am using DB Browser for Sqlite (ver 3.10.1), android studio (ver 3.0.1), minSdkVersion 19.
I am expecting the newly inserted data into the database to be saved and later seen even when i close my app and and restart the app later. Thank You!
Your issue is that DATABASE_PATH isn't being reset and is therefore empty when createDatabase is invoked.
Therefore the check to see if the database exists fails to find the database (it's looking purely for the file database_db.db at the highest level of the file system, as such the file will not exist) and the database is copied overwriting the database that has data saved into it.
I'd suggest the following changes :-
private boolean checkDatabase() {
File dbfile = new File(ourContext.getDatabasePath(DATABASE_NAME).getPath());
if ( dbfile.exists()) return true;
File dbdir = dbfile.getParentFile();
if (!dbdir.exists()) {
dbdir.mkdirs();
}
return false;
}
This has the advantage that if the databases directory doesn't exist that it will be created and that it relies solely on the database name for the path.
There is also no need for the try/catch construct.
and optionally :-
private void copyDatabase() throws IOException {
InputStream myInput = null;
OutputStream myOutput = null;
String outFileName = ourContext.getDatabasePath(DATABASE_NAME).getPath(); //<<<<<<<<<< CHANGED
try {
myInput = ourContext.getAssets().open(DATABASE_NAME);
myOutput = new FileOutputStream(outFileName);
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer)) > 0) {
myOutput.write(buffer, 0, length);
}
myOutput.flush();
myOutput.close();
myInput.close();
} catch (IOException ie) {
throw new Error("Copydatabase() error");
}
}
Note if the above are applied there is no need for the SDK version check as the getDatabasePath method gets the correct path.
Related
I try to use a sqlite database but the problem shows "no such table", the code works on some devices and some show that message.
class DatabaseHelper extends SQLiteOpenHelper {
private final String mDatabaseName;
private final Context mContext;
private final String mPath;
DatabaseHelper(Context context, String database, String path){
super(context,database,null,1);
this.mContext=context;
this.mDatabaseName=database;
this.mPath=path;
_createDatabase();
}
private void _createDatabase() {
if(_checkDatabase()){
return;
}
getReadableDatabase();
try {
_copyDatabase();
}catch (Exception e){
}
}
private void _copyDatabase() throws IOException {
InputStream inputStream = mContext.getAssets().open(mDatabaseName);
FileOutputStream fileOutputStream = new FileOutputStream(mPath+mDatabaseName);
byte[] bytes = new byte[1024];
do{
int n;
if((n=inputStream.read(bytes)) <= 0){
fileOutputStream.flush();
fileOutputStream.close();
return;
}
fileOutputStream.write(bytes,0,n);
}while (true);
}
private boolean _checkDatabase() {
return mContext.getDatabasePath(mDatabaseName).exists();
}
#Override
public void onCreate(SQLiteDatabase db) {
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
}
And database adapter look this
class DatabaseAdapter
{
private SQLiteDatabase database;
private DatabaseHelper databaseHelper;
DatabaseAdapter(Context context, String database, String path){
databaseHelper = new DatabaseHelper(context, database, path);
}
void open(){
try{
database = databaseHelper.getReadableDatabase();
}
catch (SQLiteException e)
{
database = databaseHelper.getReadableDatabase();
}
}
boolean isOpened()
{
return this.database != null && this.database.isOpen();
}
Cursor _get_rows()
{
Cursor cursor = database.rawQuery("SELECT * FROM rows ORDER BY RANDOM() LIMIT 4;", null);
cursor.moveToFirst();
return cursor;
}
}
And database controller look this
public class DatabaseController {
private static DatabaseAdapter databaseAdapter;
public static Cursor _get_rows()
{
if(!databaseAdapter.isOpened()){
databaseAdapter.open();
}
return databaseAdapter._get_rows();
}
public static void initilization(Context activity) {
String dbName= "data.db";
databaseAdapter = new DatabaseAdapter(activity.getApplicationContext(),dbName,"/data/data/"+activity.getApplicationInfo().packageName+"/databases/");
}
}
i use in activity like this
DatabaseController.initilization(this);
Cursor c = DatabaseController._get_rows();
I could not find a solution to this problem, the database was already copied to the entire directory
I suspect that the issues is that you are trapping an exception in :-
private void _createDatabase() {
if(_checkDatabase()){
return;
}
getReadableDatabase();
try {
_copyDatabase();
}catch (Exception e){
}
}
So processing continues and an empty database is created and hence no table.
The root cause might be that the databases directory might not exist. You need to look at the exception that has been trapped to determine the exact error. e.g. e.printStackTrace();
The following is how you could create the databases directory (to resolve the ENOENT (No such file or directory) exception that may be the issue) :-
e.g.
private void _copyDatabase() throws IOException {
File dir = new File(mPath); //<<<<<<<<<< ADDED
if(!dir.exists()) { //<<<<<<<<<< ADDED
dir.mkdirs(); //<<<<<<<<<< ADDED
} //<<<<<<<<<< ADDED
InputStream inputStream = mContext.getAssets().open(mDatabaseName);
FileOutputStream fileOutputStream = new FileOutputStream(mPath+mDatabaseName);
byte[] bytes = new byte[1024];
do{
int n;
if((n=inputStream.read(bytes)) <= 0){
fileOutputStream.flush();
fileOutputStream.close();
return;
}
fileOutputStream.write(bytes,0,n);
}while (true);
}
It is also inadvisable to hard code paths e.g. using :-
databaseAdapter = new DatabaseAdapter(activity.getApplicationContext(),dbName,"/data/data/"+activity.getApplicationInfo().packageName+"/databases/");
It's better to get the path using the Context's getDatabasePath method.
Note the code is in-principle code, it has not been tested or run and may therefore contain errors.
Note on the devices on which you have issues you will need to delete the database (Clear the App's data or uninstall the App) before running any amended code.
I copy DB from assets by this code:
public class DatabaseHelper extends OrmLiteSqliteOpenHelper {
private static final String DATABASE_NAME = "database.db";
private static final String DATABASE_PATH = "/data/data/"+BuildConfig.APPLICATION_ID+"/databases/";
public DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
copyFromAssets(context);
}
private void copyFromAssets(Context context) {
boolean dbexist = checkdatabase();
if (!dbexist) {
File dir = new File(DATABASE_PATH);
dir.mkdirs();
InputStream myinput = context.getAssets().open(DATABASE_NAME);
String outfilename = DATABASE_PATH + DATABASE_NAME;
Log.i(DatabaseHelper.class.getName(), "DB Path : " + outfilename);
OutputStream myoutput = new FileOutputStream(outfilename);
byte[] buffer = new byte[1024];
int length;
while ((length = myinput.read(buffer)) > 0) {
myoutput.write(buffer, 0, length);
}
myoutput.flush();
myoutput.close();
myinput.close();
}
}
}
to get Dao I use this:
public Dao<AnyItem, Integer> getDaoAnyItem() throws SQLException {
if (daoAnyItem == null) {
daoAnyItem = getDao(AnyItem.class);
}
return daoAnyItem;
}
But how to get Dao if my DB will be Password protected?
You must use SQLCipher with OrmLite, I would suggest ormlite-sqlcipher library to you
OrmLiteSqliteOpenHelper has a constructor which takes a password so change you super call to
super(context, DATABASE_NAME, null, DATABASE_VERSION, (File)null, "DB password goes here");
I would take the call to copyFromAssets(context) out of the DatabaseHelper constructor and call it before DatabaseHelper gets created i.e. first thing when the app starts up
.I start to write diet planner project and this is my database tables .I use external database and define tables foreign key there and copy it in asset folder and then connect it to my project.
standardUnit,Foods and standardFoodUnit are 3 tables which have static data and I filled them before,but EatenFood table is dynamically filled after Calculations.
I use model class and try to write databaseAdapter with androidhive database tutorial instruction.but because I started android recently I don't have any vision about it.
try to read book or online tutorial but they mixing up me more. now this is my question,I want to know for EatenFood table foreign key how can I put food-id value?I defined food_id INTEGER REFERENCES Foods ( _id ) in database before but in databaseAdapter class for insert or update or get function I don't know how can behave with this foreign key.
this is model class for EatenFood table
public class EatenFood {
int eatenfoodid;
boolean breakfast;
boolean lunch;
boolean snack;
boolean appetizers;
boolean dinner;
Data day;
String equivalent;
boolean dairy;
boolean vegetables;
boolean fruit;
boolean meat_bean_egg;
boolean bread_cereals;
boolean fat;
boolean suger;
double unitsum;
int food_id;
public boolean isAppetizers() {
return appetizers;
}
public void setAppetizers(boolean appetizers) {
this.appetizers = appetizers;
}
public Data getDay() {
return day;
}
public void setDay(Data day) {
this.day = day;
}
public double getUnitsum() {
return unitsum;
}
public void setUnitsum(double unitsum) {
this.unitsum = unitsum;
}
public int getFood_id() {
return food_id;
}
public void setFood_id(int food_id) {
this.food_id = food_id;
}
//all remaining getter and setter .........}
model class for food table
public class Foods {
int foodid;
String foodname;
boolean breakfast;
boolean lunch;
boolean snack;
boolean appetizers;
boolean dinner;
boolean mainfood;
boolean secondary;
public boolean isAppetizers() {
return appetizers;
}
public void setAppetizers(boolean appetizers) {
this.appetizers = appetizers;
}
public int getFoodid() {
return foodid;
}
public void setFoodid(int foodid) {
this.foodid = foodid;
}
//all remaining getter and setter .........}
DatabaseAdapter Functions
public class DatabaseAdapter {
private final String TAG = "DatabaseAdapter";
private DatabaseOpenHelper openHelper;
public Long insertEatenFood(EatenFood eatenfood) {
SQLiteDatabase myDataBase = null;
Long id = -1L;
try {
ContentValues values = new ContentValues();
values.put(TABLE_EATENFOOD_BREAKFAST, eatenfood.isBreakfast());
values.put(TABLE_EATENFOOD_LUNCH, eatenfood.isLunch());
values.put(TABLE_EATENFOOD_SNACK, eatenfood.isSnack());
values.put(TABLE_EATENFOOD_APPETIZERS, eatenfood.isAppetizers());
values.put(TABLE_EATENFOOD_DINNER, eatenfood.isDinner());
// values.put(TABLE_EATENFOOD_DATA, eatenfood.getDay().getClass());
values.put(TABLE_EATENFOOD_EQUIVALENT, eatenfood.getEquivalent());
values.put(TABLE_EATENFOOD_DAIRY, eatenfood.isDairy());
values.put(TABLE_EATENFOOD_VEGETABLES, eatenfood.isVegetables());
values.put(TABLE_EATENFOOD_FRUIT, eatenfood.isFruit());
values.put(TABLE_EATENFOOD_MEAT_BEAN_EGG,
eatenfood.isMeat_bean_egg());
values.put(TABLE_EATENFOOD_BREAD_CEREALS,
eatenfood.isBread_cereals());
values.put(TABLE_EATENFOOD_FAT, eatenfood.isFat());
values.put(TABLE_EATENFOOD_SUGER, eatenfood.isSuger());
values.put(TABLE_EATENFOOD_UNITSUM, eatenfood.getUnitsum());
myDataBase = openHelper.getWritableDatabase();
id = myDataBase.insert(TABLE_EATENFOOD, null, values);
} catch (Exception e) {
Log.e(TAG, "Exception: " + e.getMessage());
} finally {
if (myDataBase != null && myDataBase.isOpen())
myDataBase.close();
}
return id;
}
// update EateanFood table =====================================================
public int updateEatenFood(EatenFood eatenfood) {
SQLiteDatabase myDataBase = null;
int count = -1;
try {
myDataBase = openHelper.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(TABLE_EATENFOOD_BREAKFAST, eatenfood.isBreakfast());
values.put(TABLE_EATENFOOD_LUNCH, eatenfood.isLunch());
values.put(TABLE_EATENFOOD_SNACK, eatenfood.isSnack());
values.put(TABLE_EATENFOOD_APPETIZERS, eatenfood.isAppetizers());
values.put(TABLE_EATENFOOD_DINNER, eatenfood.isDinner());
// values.put(TABLE_EATENFOOD_DATA, eatenfood.getDay().getClass());
values.put(TABLE_EATENFOOD_EQUIVALENT, eatenfood.getEquivalent());
values.put(TABLE_EATENFOOD_DAIRY, eatenfood.isDairy());
values.put(TABLE_EATENFOOD_VEGETABLES, eatenfood.isVegetables());
values.put(TABLE_EATENFOOD_FRUIT, eatenfood.isFruit());
values.put(TABLE_EATENFOOD_MEAT_BEAN_EGG,
eatenfood.isMeat_bean_egg());
values.put(TABLE_EATENFOOD_BREAD_CEREALS,
eatenfood.isBread_cereals());
values.put(TABLE_EATENFOOD_FAT, eatenfood.isFat());
values.put(TABLE_EATENFOOD_SUGER, eatenfood.isSuger());
values.put(TABLE_EATENFOOD_UNITSUM, eatenfood.getUnitsum());
count = myDataBase
.update(TABLE_EATENFOOD, values, TABLE_EATENFOOD_ID + "=?",
new String[] { String.valueOf(eatenfood
.getEatenfoodid()) });
} catch (Exception e) {
Log.e(TAG, "Exception: " + e.getMessage());
} finally {
myDataBase.close();
}
return count;
}
// Getting All EatenFood ================================================
public ArrayList<EatenFood> getEatenfoods() {
ArrayList<EatenFood> result = null;
SQLiteDatabase myDataBase = null;
Cursor cursor = null;
try {
myDataBase = openHelper.getWritableDatabase();
cursor = myDataBase.query(TABLE_EATENFOOD, new String[] { "*" }, null, null,
null, null, null);
if (cursor.moveToFirst()) {
result = new ArrayList<EatenFood>();
do {
result.add(extractEatenFood(cursor));
} while (cursor.moveToNext());
}
} catch (Exception e) {
Log.e(TAG, "Exception: " + e.getMessage());
}
finally {
if (cursor != null) {
cursor.close();
}
myDataBase.close();
}
return result;
}
// extractEatenFood=============================================================
private EatenFood extractEatenFood(Cursor cursor){
EatenFood eatenfood = new EatenFood();
eatenfood.setEatenfoodid(cursor.getInt(cursor.getColumnIndex(TABLE_EATENFOOD_ID)));
eatenfood.setBreakfast(cursor.getInt(cursor.getColumnIndex(TABLE_EATENFOOD_BREAKFAST)) != 0);
eatenfood.setLunch(cursor.getInt(cursor.getColumnIndex(TABLE_EATENFOOD_LUNCH))!=0);
eatenfood.setSnack(cursor.getInt(cursor.getColumnIndex(TABLE_EATENFOOD_SNACK))!=0);
eatenfood.setAppetizers(cursor.getInt(cursor.getColumnIndex(TABLE_EATENFOOD_APPETIZERS))!=0);
eatenfood.setDinner(cursor.getInt(cursor.getColumnIndex(TABLE_EATENFOOD_DINNER))!=0);
// ???????????????????????? baraye day k sabt beshe
eatenfood.setEquivalent(cursor.getString(cursor.getColumnIndex(TABLE_EATENFOOD_EQUIVALENT)));
eatenfood.setDairy(cursor.getInt(cursor.getColumnIndex(TABLE_EATENFOOD_DAIRY))!=0);
eatenfood.setVegetables(cursor.getInt(cursor.getColumnIndex(TABLE_EATENFOOD_VEGETABLES))!=0);
eatenfood.setFruit(cursor.getInt(cursor.getColumnIndex(TABLE_EATENFOOD_FRUIT))!=0);
eatenfood.setBread_cereals(cursor.getInt(cursor.getColumnIndex(TABLE_EATENFOOD_BREAD_CEREALS))!=0);
eatenfood.setFat(cursor.getInt(cursor.getColumnIndex(TABLE_EATENFOOD_FAT))!=0);
eatenfood.setSuger(cursor.getInt(cursor.getColumnIndex(TABLE_EATENFOOD_SUGER))!=0);
eatenfood.setFood_id(cursor.getInt(cursor.getColumnIndex(TABLE_EATENFOOD_F_FOODID)));
return eatenfood ;
}
Whenever you want to add a food into you're eatenfood table. You have to call getFoodid function on you're specific food object and get the food_id and after that insert into database with insertEatenFood function in you're DatabaseAdapter class.
It's better you mention you're whole example of you're question that's makes it more easy to help you.
Maybe you got a problem about how can you find the food_id's that you want to insert into you're eatenfood table. It's better to write you're algorithms after that you find out which food_id's gonna be needed for you're different users.
I'm using the code below to copy the data containing files and folders with subfolders in them to data directory of my application but I get exception telling the destination location does not exist however FileOutputStream method should make the destination folders according to javadoc for this method:
Constructs a new FileOutputStream that writes to path. The file will be truncated if it exists, and created if it doesn't exist.
the code is :
private void copyFileOrDir(String path) {
AssetManager assetManager = this.getAssets();
String assets[] = null;
try {
assets = assetManager.list(path);
if (assets.length == 0) {
copyFile(path);
} else {
String fullPath = "/data/data/" + this.getPackageName() + "/" + path;
File dir = new File(fullPath);
if (!dir.exists())
dir.mkdir();
File innerDir;
for (int i = 0; i < assets.length; ++i) {
copyFileOrDir(path + "/" + assets[i]);
}
}
} catch (IOException ex) {
Log.e("tag", "I/O Exception", ex);
}
}
private void copyFile(String filename) {
AssetManager assetManager = this.getAssets();
InputStream in = null;
OutputStream out = null;
try {
in = assetManager.open(filename);
String newFileName = "/data/data/" + this.getPackageName() + "/" + filename;
out = new FileOutputStream(newFileName);
byte[] buffer = new byte[1024];
int read;
while ((read = in.read(buffer)) != -1) {
out.write(buffer, 0, read);
}
in.close();
in = null;
out.flush();
out.close();
out = null;
} catch (Exception e) {
//getting exception here...
Log.e("mgh", e.getMessage());
}
}
logcat errors are like below for any folder :
09-06 15:14:20.981: E/mgh(19262): /data/data/ir.example.sampleapplication/pzl/ui/css/main.css: open failed: ENOENT (No such file or directory)
/*I m using this code for copy data from assets folder just try it */
public class DataBaseHelper extends SQLiteOpenHelper{
private static String DB_PATH = "/data/data/com.astrobix.numerodaily/databases/";
private static String DB_NAME = "Astrobix";
private static final String tag = "DatabaseHelperClass";
public static SQLiteDatabase myDataBase;
public final Context myContext;
public static String Table_Name="Prediction";
public static final String COL_ID="ID";
public static final String COL_HEAD="HEAD";
public static final String COL_VALUE="VALUE";
private static final String TABLE_QUESTIONS ="Prediction";
private static final String Create_Table="create table if not exists "
+Table_Name
+"("
+COL_ID
+" INTEGER primary key autoincrement , "
+COL_HEAD
+" TEXT, "
+COL_VALUE
+ " VARCHAR); ";
// public static String lastrecord;
// public static String ratio="7:7";
public DataBaseHelper(Context context) {
super(context, DB_NAME, null, 1);
this.myContext = context;
}
/**
* Creates a empty database on the system and rewrites it with your own database.
* */
public void createDataBase() throws IOException{
boolean dbExist = checkDataBase();
if(dbExist){
//do nothing - database already exist
}else{
//By calling this method and empty database will be created into the default system path
//of your application so we are gonna be able to overwrite that database with our database.
this.getReadableDatabase();
try {
copyDataBase();
} catch (IOException e) {
throw new Error("Error copying database");
}
}
}
/**
* Check if the database already exist to avoid re-copying the file each time you open the application.
* #return true if it exists, false if it doesn't
*/
private boolean checkDataBase(){
SQLiteDatabase checkDB = null;
try{
String myPath = DB_PATH + DB_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
}catch(SQLiteException e){
//database does't exist yet.
}
if(checkDB != null){
checkDB.close();
}
return checkDB != null ? true : false;
/* File dbFile = new File(DB_PATH + DB_NAME);
return dbFile.exists();*/
}
/**
* Copies your database from your local assets-folder to the just created empty database in the
* system folder, from where it can be accessed and handled.
* This is done by transfering bytestream.
* */
private void copyDataBase() throws IOException{
//Open your local db as the input stream
InputStream myInput = myContext.getAssets().open("Astrobix.sqlite");
// Path to the just created empty db
String outFileName = DB_PATH + DB_NAME;
//Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
//transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer))>0){
myOutput.write(buffer, 0, length);
}
//Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
}
public void openDataBase() throws SQLException{
//Open the database
String myPath = DB_PATH + DB_NAME;
myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE );
}
#Override
public synchronized void close() {
if(myDataBase != null)
myDataBase.close();
super.close();
}
#Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(Create_Table);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
if (db != null)
onCreate(db);
}
I try to copy SQLite database from assets directory to access it later. But I fail to do it!
public class DatabaseAdapter {
private static String DB_PATH = "/data/data/com.mypackage/databases/";
private static String DB_NAME = "database.sqlite";
private static String TABLE_NAME = "content_table";
private SQLiteDatabase database = null;
private final Context context;
public DatabaseAdapter(Context context){
this.context = context;
}
private void openDatabase() throws SQLiteException{
DatabaseHelper databaseHelper = new DatabaseHelper(context, DB_NAME);
SQLiteDatabase db = null;
if(!checkDatabase()){
try{
//Tried to create db before copying, so file should exist
db = databaseHelper.getReadableDatabase();
db.close();
copyDatabase();
}catch(IOException exception){
Log.d("DatabaseAdapter", "Error copying DB: "+exception);
}
}
database = SQLiteDatabase.openDatabase(DB_PATH+DB_NAME, null, SQLiteDatabase.OPEN_READONLY);
}
private void closeDatabase(){
database.close();
}
public ArrayList<String> queryCategories(){
try{
openDatabase();
}catch(SQLiteException exc){
exc.printStackTrace();
}
//.............................
return result;
}
private boolean checkDatabase(){
File dbFile = new File(DB_PATH + DB_NAME);
return dbFile.exists();
}
private void copyDatabase() throws IOException{
InputStream inputStream = context.getAssets().open(DB_NAME);
String outFileName = DB_PATH + DB_NAME;
OutputStream outputStream = new FileOutputStream(outFileName);
byte[] buffer = new byte[1024];
int length;
while ((length = inputStream.read(buffer))>0){
outputStream.write(buffer, 0, length);
}
outputStream.flush();
outputStream.close();
inputStream.close();
}
}
DatabaseHelper is simple:
ublic class DatabaseHelper extends SQLiteOpenHelper {
public DatabaseHelper(Context context, String name){
super(context, name, null, 1);
}
#Override
public void onCreate(SQLiteDatabase arg0) {
// TODO Auto-generated method stub
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
}
}
Tried everything! I tried playing with extention! But I still get an error:
Error copying DB: java.io.FileNotFoundException: /data/data/com.mypackage/databases/database.sqlite (No such file or directory)
I checked on emulator, my file is there, so I should be able to write to it!
Please, any help! It's driving me nuts!
UPD I tried to place it on SD card and it worked. But still can't get why I can't write it to app data folder.
I use this Helper and works fine:
public class DBHelper extends SQLiteOpenHelper{
private final static String DB_PATH = "/data/data/[YOUR PACKAGE HERE]/databases/";
String dbName;
Context context;
File dbFile;
public DBHelper(Context context, String dbName, CursorFactory factory,
int version) {
super(context, dbName, factory, version);
this.context = context;
this.dbName = dbName;
dbFile= new File(DB_PATH + dbName);
}
#Override
public synchronized SQLiteDatabase getWritableDatabase() {
if(!dbFile.exists()){
SQLiteDatabase db = super.getWritableDatabase();
copyDataBase(db.getPath());
}
return super.getWritableDatabase();
}
#Override
public synchronized SQLiteDatabase getReadableDatabase() {
if(!dbFile.exists()){
SQLiteDatabase db = super.getReadableDatabase();
copyDataBase(db.getPath());
}
return super.getReadableDatabase();
}
#Override
public void onCreate(SQLiteDatabase db) {}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {}
private void copyDataBase(String dbPath){
try{
InputStream assestDB = context.getAssets().open("databases/"+dbName);
OutputStream appDB = new FileOutputStream(dbPath,false);
byte[] buffer = new byte[1024];
int length;
while ((length = assestDB.read(buffer)) > 0) {
appDB.write(buffer, 0, length);
}
appDB.flush();
appDB.close();
assestDB.close();
}catch(IOException e){
e.printStackTrace();
}
}
}
Take into account that the file extension of a database is .db and that my databases are into assets/databases/
I have the same problem and I have fixed it with another approach.
At the beginning, I declared the database path as everyone did:
dbPath="data/data/<my package name>/databases/data.db"
This is an exactly path, no mistake. But It' always fail when I try to open the OutPutFileStream to copy database. I don't know why. And then, I change the way to open the database as below:
dbPath = context.getDatabasePath(dbName);
OutputStream myOutput = new FileOutputStream(dbPath.getAbsolutePath());
The problem has ben solved. So surprise.
Hope this helps.
public static void copyDatabase(final Context ctx, String dbName) {
if (ctx != null) {
File f = ctx.getDatabasePath(dbName);
if (!f.exists()) {
// check databases exists
if (!f.getParentFile().exists())
f.getParentFile().mkdir();
try {
InputStream in = ctx.getAssets().open(dbName);
OutputStream out = new FileOutputStream(f.getAbsolutePath());
byte[] buffer = new byte[1024];
int length;
while ((length = in.read(buffer)) > 0) {
out.write(buffer, 0, length);
}
in.close();
out.close();
Logger.i("Database copy successed! " + f.getPath());
} catch (Exception ex) {
Logger.e(ex);
}
}
}
}
Please check the databases folder before your OutputStream.
like this,
File databaseFile = new File(context.getFilesDir().getAbsolutePath()
.replace("files", "databases"));
// check if databases folder exists, if not create it.
if (!databaseFile.exists()){
databaseFile.mkdir();
}