Database onUpgrade method is never called - java

I'm trying to upgrade my database from version 1 to version 2. I'm assigning DATABASE_VERSION = 2 (first version was assigned too) but onUpgrade never called.
May be there is an obvious mistake in the code, but I can't see it beacause I'm trying to solve this problem for a long time.
Here is the code of database helper class:
public class DatabaseHelper extends SQLiteOpenHelper {
private static final int DATABASE_VERSION = 2;
public static String DB_PATH;
public static String DB_NAME = "db.sqlite3";
public SQLiteDatabase database;
public final Context context;
public DatabaseHelper(Context context) {
super(context, DB_NAME, null, DATABASE_VERSION);
this.context = context;
File direct = new File(Environment.getExternalStorageDirectory()
+ "/.test");
if (!direct.exists()) {
if (direct.mkdir())
;
}
DB_PATH = Environment.getExternalStorageDirectory().getPath()
+ "/.test/";
}
public void createDataBase() {
boolean dbExist = checkDataBase();
if (!dbExist) {
try {
copyDataBase();
} catch (IOException e) {
Log.e(this.getClass().toString(), "Copying error");
throw new Error("Error copying database!");
}
}
}
private boolean checkDataBase() {
SQLiteDatabase checkDb = null;
try {
String path = DB_PATH + DB_NAME;
checkDb = SQLiteDatabase.openDatabase(path, null,
SQLiteDatabase.OPEN_READONLY);
} catch (SQLException e) {
Log.e(this.getClass().toString(), "Error while checking db");
}
if (checkDb != null) {
checkDb.close();
}
return checkDb != null;
}
private void copyDataBase() throws IOException {
InputStream externalDbStream = context.getAssets().open(
"databases/" + DB_NAME);
String outFileName = DB_PATH + DB_NAME;
OutputStream localDbStream = new FileOutputStream(outFileName);
byte[] buffer = new byte[1024];
int bytesRead;
while ((bytesRead = externalDbStream.read(buffer)) > 0) {
localDbStream.write(buffer, 0, bytesRead);
}
localDbStream.close();
externalDbStream.close();
}
public SQLiteDatabase openDataBase() throws SQLException {
String path = DB_PATH + DB_NAME;
if (database == null) {
createDataBase();
database = SQLiteDatabase.openDatabase(path, null,
SQLiteDatabase.OPEN_READONLY);
}
return database;
}
// some unimportant methods
#Override
public void onCreate(SQLiteDatabase db) {
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
Log.w("myLogs", " --- onUpgrade database --- ");
}
In Activity I call database like this:
DatabaseHelper dbOpenHelper = new DatabaseHelper(this);
SQLiteDatabase database = dbOpenHelper.openDataBase();
Where is my mistake?
Help, please.
UPD: database.getVersion() returns 0
Updated openDataBase() method (it's working):
public SQLiteDatabase openDataBase() throws SQLException {
String path = DB_PATH + DB_NAME;
if (database == null) {
createDataBase();
database = SQLiteDatabase.openDatabase(path, null,
SQLiteDatabase.OPEN_READWRITE);
this.getWritableDatabase();
}
return database;
}

Local database version will always be 0 and onUpgrade will not be called, because you never called getWritableDatabase/getReadableDatabase, which will bump version and return local db.
So you need:
make call getReadableDatabase(); in your contructor/oncreate, just to trigger process, in case db version is changed
or
manually check sdcard version, db.getVersion(); compare to current version - DATABASE_VERSION. And do what ever you need to do - upgrade or downgrade.

Related

External database access, my app crashes

Yes I have searched for many solutions for days. My still persisting problem is my app crashes at start when I am trying to access an external database (created through "DB Browser for Sqlite" named "test.db").
The sole purpose is of course to prepopulate my app with some data.
I have kept the database file on assets folder in android studio. Finally I have implemented a helper class to access the database.
Here is the helper class:
public class DataBaseHelper extends SQLiteOpenHelper {
private static final String DATABASE_NAME = "test.db";
private static final int DATABASE_VERSION = 1;
private static String DATABASE_PATH = "";
private SQLiteDatabase myDataBase;
private final Context myContext;
public DataBaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
this.myContext = context;
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 void createDatabase() throws IOException {
createDB();
}
private void createDB() {
boolean dbExists = checkDatabase();
if (dbExists) {
//do nothing
} else {
this.getReadableDatabase();
try {
copyDatabase();
} catch (IOException ie) {
throw new Error("Error copying database");
}
}
}
private boolean checkDatabase() {
SQLiteDatabase checkDB = null;
try {
String myPath = DATABASE_PATH + DATABASE_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
checkDB.setLocale(Locale.getDefault());
} catch (SQLiteException e) {
throw new Error("SQLite exception");
}
if (checkDB != null) {
checkDB.close();
}
return checkDB != null;
}
private void copyDatabase() throws IOException {
InputStream myInput = null;
OutputStream myOutput = null;
String outFileName = DATABASE_PATH + DATABASE_NAME;
try{
myInput = myContext.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 run error ");
}
}
#Override
public synchronized void close() {
if(myDataBase != null){
myDataBase.close();
}
super.close();
}
}
In the Main activity I have just called the createDatabase() method of the helper class. The code being below:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
DataBaseHelper myDbHelper = new DataBaseHelper(this);
try{
myDbHelper.createDatabase();
}catch (IOException ioe){
throw new Error("Unable to CREATE DATABASE");
}
}
}
The logcat indicates the problem as:
AndroidRuntime: FATAL EXCEPTION: main java.lang.Error: SQLite
exception at DataBaseHelper.checkDatabase(DataBaseHelper.java:79) at
DataBaseHelper.createDB(DataBaseHelper.java:59) at
DataBaseHelper.createDatabase(DataBaseHelper.java:55) at
MainActivity.onCreate(MainActivity.java:18)
which points to my checkDatabase() method. But now I am not able to sort out the problem.
I am using Android Studio 3.0.1, DB Browser for Sqlite 3.10.1, Min API level used 17.
Please Help!
Try This
public static final String DATABASE_NAME = "abc.db";
public final static String DATABASE_PATH = "/data/data/"+ PACKAGE_NAME +
"/databases/";
public static final int DATABASE_VERSION = 1;
public void createDatabase() {
boolean dbExist1 = checkDataBase();
if (!dbExist1) {
this.getReadableDatabase();
try {
this.close();
copyDataBase();
} catch (IOException e) {
throw new Error("Error copying database");
}
}
}
// Check database already exist or not
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;
}
// Copies your database from your local assets-folder to the just created
// empty database in the system folder
public void copyDataBase() throws IOException {
String outFileName = DATABASE_PATH + DATABASE_NAME;
OutputStream myOutput = new FileOutputStream(outFileName);
InputStream myInput = mContext.getAssets().open(DATABASE_NAME);
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer)) > 0) {
myOutput.write(buffer, 0, length);
}
myInput.close();
myOutput.flush();
myOutput.close();
}

How to get data from a sqllite database and store it in ListView

I have a data base I need to read data from it and view it in a list view it contain some tables from them a table named "main_categories" which has one field called "category_name" which is the primary key
this is the DataAdapter:
public DataAdapter(Context context) {
this.mContext = context;
mDbHelper = new DataBaseHelper(mContext);
}
public DataAdapter createDatabase() throws SQLException {
try {
mDbHelper.createDataBase();
} catch (IOException mIOException) {
Log.e(TAG, mIOException.toString() + " UnableToCreateDatabase");
throw new Error("UnableToCreateDatabase");
}
return this;
}
public DataAdapter open() throws SQLException {
try {
mDbHelper.openDataBase();
mDbHelper.close();
mDb = mDbHelper.getReadableDatabase();
} catch (SQLException mSQLException) {
Log.e(TAG, "open >>" + mSQLException.toString());
throw mSQLException;
}
return this;
}
public void close() {
mDbHelper.close();
}
public Cursor getTestData() {
try {
String sql = "SELECT * FROM myTable";
Cursor mCur = mDb.rawQuery(sql, null);
if (mCur != null) {
mCur.moveToNext();
}
return mCur;
} catch (SQLException mSQLException) {
Log.e(TAG, "getTestData >>" + mSQLException.toString());
throw mSQLException;
}
}
}
and this is the DataBaseHelper:
public class DataBaseHelper extends SQLiteOpenHelper
{
private static String TAG = "DataBaseHelper"; // Tag just for the LogCat window
//destination path (location) of our database on device
private static String DB_PATH = "";
private static String DB_NAME ="my_knowledge";// Database name
private SQLiteDatabase mDataBase;
private final Context mContext;
public DataBaseHelper(Context context)
{
super(context, DB_NAME, null, 1);// 1? Its database Version
if(android.os.Build.VERSION.SDK_INT >= 17){
DB_PATH = context.getApplicationInfo().dataDir + "/databases/";
}
else
{
DB_PATH = context.getApplicationInfo().dataDir + "/databases/";
}
this.mContext = context;
}
public void createDataBase() throws IOException
{
//If the database does not exist, copy it from the assets.
boolean mDataBaseExist = checkDataBase();
if(!mDataBaseExist)
{
this.getReadableDatabase();
this.close();
try
{
//Copy the database from assests
copyDataBase();
Log.e(TAG, "createDatabase database created");
}
catch (IOException mIOException)
{
throw new Error("ErrorCopyingDataBase");
}
}
}
//Check that the database exists here: /data/data/your package/databases/Da Name
private boolean checkDataBase()
{
File dbFile = new File(DB_PATH + DB_NAME);
//Log.v("dbFile", dbFile + " "+ dbFile.exists());
return dbFile.exists();
}
//Copy the database from assets
private void copyDataBase() throws IOException
{
InputStream mInput = mContext.getAssets().open(DB_NAME);
String outFileName = DB_PATH + DB_NAME;
OutputStream mOutput = new FileOutputStream(outFileName);
byte[] mBuffer = new byte[1024];
int mLength;
while ((mLength = mInput.read(mBuffer))>0)
{
mOutput.write(mBuffer, 0, mLength);
}
mOutput.flush();
mOutput.close();
mInput.close();
}
//Open the database, so we can query it
public boolean openDataBase() throws SQLException
{
String mPath = DB_PATH + DB_NAME;
//Log.v("mPath", mPath);
mDataBase = SQLiteDatabase.openDatabase(mPath, null, SQLiteDatabase.CREATE_IF_NECESSARY);
//mDataBase = SQLiteDatabase.openDatabase(mPath, null, SQLiteDatabase.NO_LOCALIZED_COLLATORS);
return mDataBase != null;
}
#Override
public synchronized void close()
{
if(mDataBase != null)
mDataBase.close();
super.close();
}
#Override
public void onCreate(SQLiteDatabase sqLiteDatabase) {
}
#Override
public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {
}
}
and this is the main activity for now:
public class MainActivity extends AppCompatActivity {
SQLiteDatabase sqLiteDatabase;
private static String DB_NAME ="my_knowledge"; // Database name
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ListView list = findViewById(R.id.main_list);
DataAdapter mDbHelper = new DataAdapter(this);
mDbHelper.createDatabase();
mDbHelper.open();
Cursor testdata = mDbHelper.getTestData();
mDbHelper.close();
}
}
I want to know a way to store the data in the tables of the array (for example "main_categories") and view them with the list view
Depending on your table column type
List<String> temp;
testdata.moveToFirst();
do {
temp.add(testdata.getString(0));
} while (testdata.moveToNext());
Your cursor testdata has the first row in testdata.moveToFirst(); and each column is associated with column index i.e. 0, 1 etc.
testdata.moveToNext(); will have successive rows.
A couple of things:
First of, I would consider adding a query method to your DataBaseHelper class instead of using a rawQuery, something like:
Cursor query(String table, String[] projection, String where, String orderBy) {
return getReadableDatabase().query(table, projection, where, null, null, null, orderBy);
}
You can call the query method inside mDbHelper.getTestData() and use the Cursor object to populate your list.
Take a look at using a Cursor Loader?
to do get the data out of the cursor and into your adapter.

onUpgrade() and onCreate() method do not invoke when creating a new version of database in SQLiteOpenHelper

I am trying to create a new version of database in my android app. But although I change the version of database from previous version (2) to a new version (3) it doesn't invoke onUpgrade() and onCreate() . It just invoke three times the constructor. I do not understand why constructor invoked three times and also why onUpgrade() and onCreate() did not invoke?
I also tried with new database version code but result is same.
Here is my code.
public class DatabaseHelper extends SQLiteOpenHelper {
private static String PACKAGE_NAME;
private static String DB_PATH;
private static String DB_NAME = "mydata.db";
private SQLiteDatabase myDataBase;
private final Context myContext;
public DatabaseHelper(Context context) {
super(context, DB_NAME, null, 3);
this.myContext = context;
Log.e("UPDATED3", "CONSTRUCTOR");
PACKAGE_NAME = myContext.getPackageName();
DB_PATH = "/data/data/" + PACKAGE_NAME + "/databases/";
}
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");
}
}
}
private boolean checkDataBase() {
SQLiteDatabase checkDB = null;
try {
String myPath = DB_PATH + DB_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READWRITE);
} catch (SQLiteException e) {
// database does't exist yet.
}
if (checkDB != null) {
checkDB.close();
}
return checkDB != null ? true : false;
}
private void copyDataBase() throws IOException {
// Open your local db as the input stream
InputStream myInput = myContext.getAssets().open(DB_NAME);
// 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) {
Log.e("UPDATED3", "ONCREATE");
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
Log.e("UPDATED3", "UPDATED THE DATABASE");
}
}
I use my database this(showing below) way in any activity.
DatabaseHelper databaseHelper = new DatabaseHelper(getApplicationContext());
try {
databaseHelper.createDataBase();
databaseHelper.openDataBase();
} catch (IOException e) {
Toast.makeText(getApplicationContext(), "Error: " + e.getMessage(),
Toast.LENGTH_LONG).show();
e.printStackTrace();
}

how to make MyDBHelper As Global Variable?

This is my DataBaseHelper.java
package com.example.abc2;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import android.content.Context;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
public class DataBaseHelper extends SQLiteOpenHelper{
//The Android's default system path of your application database.
private static String DB_PATH = "/data/data/com.example.abc2/databases/";
private static String DB_NAME = "DB_BusData";
private SQLiteDatabase myDataBase;
private final Context myContext;
/**
* Constructor
* Takes and keeps a reference of the passed context in order to access to the application assets and resources.
* #param context
*/
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;
}
/**
* 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(DB_NAME);
// 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_READONLY);
}
#Override
public synchronized void close() {
if(myDataBase != null)
myDataBase.close();
super.close();
}
#Override
public void onCreate(SQLiteDatabase db) {
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
// Add your public helper methods to access and get content from the database.
// You could return cursors by doing "return myDataBase.query(....)" so it'd be easy
// to you to create adapters for your views.
}
MainActivity.java
public void DatabaseConn(){
DataBaseHelper myDbHelper = new DataBaseHelper(this.getApplicationContext());
myDbHelper = new DataBaseHelper(this);
try {
myDbHelper.createDataBase();
} catch (IOException ioe) {
throw new Error("Unable to create database");
}
try {
myDbHelper.openDataBase();
}catch(SQLException sqle){
throw sqle;
}
SQLiteDatabase db = myDbHelper.getReadableDatabase();
//SQLiteDatabase db = SQLiteDatabase.openDatabase("/data/data/com.example.abc2/databases/DB_BusData", null, 0);
Cursor c = db.rawQuery("SELECT * FROM Tbl_Driver", null);
if(c.moveToFirst()) {
String username = c.getString(c.getColumnIndex("Driver_Code")).trim();
String password = c.getString(c.getColumnIndex("Driver_Name")).trim();
Log.d(null, username);
}
db.close();
}
Any Idea to make my myDbHelper as global variable, otherwise every function i want to call the database i need to declare it, it is inconvenience.
Just add this
DataBaseHelper myDbHelper = new DataBaseHelper(this.getApplicationContext());
Over onCreate in your MainActivity, and remove it from public void DatabaseConn(){.
Create a Singleton Database class:
public class Database extends SQLiteOpenHelper {
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "yourDatabaseName";
//Declare a String for each Table name
public static final String TABLE_NAME1 = "tableName1";
public static final String TABLE_NAME2 = "tableName2";
//Declare a SQL string for create each table
private static final String CREATE_TABLE1 =
"CREATE TABLE if not exists " + TABLE_NAME1 ..............";
private static final String CREATE_TABLE2 =
"CREATE TABLE if not exists " + TABLE_NAME2 .................";
private static Database Singleton = null;
private Context context;
private static SQLiteDatabase Db;
private Database(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
this.context = context;
}
public static synchronized Database getInstance(Context c){
if(Singleton == null) {
Singleton = new Database(c.getApplicationContext());
Db = Singleton.getWritableDatabase();
}
return Singleton;
}
public SQLiteDatabase getDatabase() {
return Db;
}
public synchronized void close() {
if (Singleton != null && Db.isOpen()) Db.close();
}
#Override
protected void finalize() throws Throwable {
try{
close();
}
finally{
super.finalize();
}
#Override
public void onCreate(SQLiteDatabase db) {
//Create Tables
db.execSQL(CREATE_TABLE1);
db.execSQL(CREATE_TABLE2);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
}
}
When you need a database object:
SQLiteDatabase Db = Database.getInstance(context).getDatabase();

How to populate SQLite db with images, and retrieve images from it?

I have 100 images in my Assets folder. I would like to set an image to the imageview, and below four buttons with 4 possible answers to connect with the image (one correct, of course). What I was thinking, I have a similar quiz game already done, I'm using SQLite database for question and answers. So, is there a way I could use sqlite database for this, but only where my question is in database I would place some term or an integer, for example 1 for image_1.png, 2 for image_2.png and so on.
Or another scenario is to prepopulate database with images, but I don't know if that's even possible or how to do it.
Is there a way to rewrite my db helper to use it with this? Here's my db helper and testAdapter:
public class DataBaseHelper extends SQLiteOpenHelper
{
private static String TAG = "DataBaseHelper"; // Tag just for the LogCat window
//destination path (location) of our database on device
private static String DB_PATH = "/data/data/rs.androidaplikacijekvizopstekulture/databases/";
private static String DB_NAME ="pitanja.sqlite";// Database name
private static SQLiteDatabase mDataBase;
private final Context mContext;
private static final String KEY_ID = "_ID";
private static final String TABLE_NAME = "tblPitanja";
public DataBaseHelper(Context mojContext)
{
super(mojContext, DB_NAME, null, 1);// 1? its Database Version
DB_PATH = mojContext.getApplicationInfo().dataDir + "/databases/";
this.mContext = mojContext;
}
public void createDataBase() throws IOException
{
//If database not exists copy it from the assets
this.getReadableDatabase();
this.close();
try
{
//Copy the database from assests
copyDataBase();
Log.e(TAG, "createDatabase database created");
}
catch (IOException mIOException)
{
throw new Error("ErrorCopyingDataBase");
}
}
/*Check that the database exists here: /data/data/your package/databases/Da Name
private boolean checkDataBase()
{
File dbFile = new File(DB_PATH + DB_NAME);
//Log.v("dbFile", dbFile + " "+ dbFile.exists());
return dbFile.exists();
}
*/
//Copy the database from assets
private void copyDataBase() throws IOException
{
InputStream mInput = mContext.getAssets().open(DB_NAME);
String outFileName = DB_PATH + DB_NAME;
OutputStream mOutput = new FileOutputStream(outFileName);
byte[] mBuffer = new byte[1024];
int mLength;
while ((mLength = mInput.read(mBuffer))>0)
{
mOutput.write(mBuffer, 0, mLength);
}
mOutput.flush();
mOutput.close();
mInput.close();
}
//Open the database, so we can query it
public boolean openDataBase() throws SQLException
{
String mPath = DB_PATH + DB_NAME;
//Log.v("mPath", mPath);
mDataBase = SQLiteDatabase.openDatabase(mPath, null, SQLiteDatabase.CREATE_IF_NECESSARY);
//mDataBase = SQLiteDatabase.openDatabase(mPath, null, SQLiteDatabase.NO_LOCALIZED_COLLATORS);
return mDataBase != null;
}
#Override
public void close()
{
if(mDataBase != null)
mDataBase.close();
super.close();
}
#Override
public void onCreate(SQLiteDatabase arg0) {
}
#Override
public void onUpgrade(SQLiteDatabase arg0, int arg1, int arg2) {
Log.w("DataBaseHelper", "Upgrading database!!!!!");
onCreate(arg0);
}
}
And here's testAdaper:
public class TestAdapter
{
protected static final String TAG = "DataAdapter";
private final Context mContext;
private SQLiteDatabase mDb;
private DataBaseHelper mDbHelper;
public TestAdapter(Context context)
{
this.mContext = context;
mDbHelper = new DataBaseHelper(mContext);
}
public TestAdapter createDatabase() throws SQLException
{
try
{
mDbHelper.createDataBase();
}
catch (IOException mIOException)
{
Log.e(TAG, mIOException.toString() + " UnableToCreateDatabase");
throw new Error("UnableToCreateDatabase");
}
return this;
}
public TestAdapter open() throws SQLException
{
try
{
mDbHelper.openDataBase();
mDbHelper.close();
mDb = mDbHelper.getReadableDatabase();
}
catch (SQLException mSQLException)
{
Log.e(TAG, "open >>"+ mSQLException.toString());
throw mSQLException;
}
return this;
}
public void close()
{
mDbHelper.close();
}
public Cursor getTestData(String whereClause)
{;
try
{
String sql ="SELECT * FROM tblPitanja WHERE 1 = 1 " + whereClause + " ORDER BY RANDOM() LIMIT 1";
Cursor mCur = mDb.rawQuery(sql, null);
if (mCur!=null)
{
mCur.moveToNext();
}
return mCur;
}
catch (SQLException mSQLException)
{
Log.e(TAG, "getTestData >>"+ mSQLException.toString());
throw mSQLException;
}
}
}
You can save the images in sqlite by using blob datatype. Use SQLite manager (firefox plugin) to pre-populate your database on a computer. Then you just need the db file in assets folder, and not those 100 images!
Check this:
how to store Image as blob in Sqlite & how to retrieve it?
Another way (faster) is to store images in an external folder and then enter its URL in the database.
Since you have images in assets already I would suggest you to save only the names of the associated image in the sqlite. I prefer always to avoid saving blob in sqlite. You can always get the correct name and load it into the imageview directly from the database.
EDIT :
your code can be as simple as this.
Cursor getname = db.rawQuery("Select * from table_name where QuestionID = ...");
if(getname.movetofirst())
{
String drawablename = getname.getString(getname.getColumnIndex("PicName"));
ImageView iw= (ImageView)findViewById(R.id.imageView1);
int resID = getResources().getIdentifier(drawableName, "drawable", getPackageName());
iw.setImageResource(resID);
}

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