Error When I try to open SQLite database pre-created in the assets folder

Question

I have a database in SQLite precreated and inserted in assets folder, unfortunately I cannot access the database.

When I try to use a command to access the DB, for example

 DataBaseHelper myDbHelper = new DataBaseHelper(this);
         myDbHelper = new DataBaseHelper(this);

         try {

            myDbHelper.openDataBase();

        }catch(SQLException sqle){

            throw sqle;

        }

I get this error:

E/AndroidRuntime(5390): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.mysoftware.app/com.mysoftware.app.Home}: android.database.sqlite.SQLiteException: unable to open database file

My DataBaseHelper class is:

public class DataBaseHelper extends SQLiteOpenHelper{

    private static String DB_PATH = "/data/data/com.mysoftware.app/databases/";

    private static String DB_NAME = "DBTestate";

    private SQLiteDatabase myDataBase; 

    private final Context myContext;


    public DataBaseHelper(Context context) {

        super(context, DB_NAME, null, 1);
        this.myContext = context;
    }   

    public void createDataBase() throws IOException{

        boolean dbExist = checkDataBase();
        SQLiteDatabase db_Read = null;

        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();
            db_Read = this.getReadableDatabase(); 
            db_Read.close();

            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_READONLY);

        }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_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) {

    }
    ....

}

My database structure : SQLite view of db that I have inserted in assets folder

@AndreaF...It sounds real stoopid but have a check with the DB name — Kunal Shah, Sep 12 '12 at 12:04
http://stackoverflow.com/questions/9109438/how-to-use-existing-database-with-android-app/9109728#9109728 — Yaqub Ahmad, Sep 12 '12 at 15:01
@YaqubAhmad I have followed the tutorial of your link before post. My implementation is based on that. Unfortunately doesn't work. — AndreaF, Sep 12 '12 at 15:47

score 0 · Answer 1 · answered Sep 12 '12 at 12:08

just use this ,this is running code and will make a similar db as that of asset folder

    private static String LOG_TAG = "DATABASE";
private static String DB_PATH = "/data/data/you_package_name/databases/";
private static String DB_NAME = "Your_DB_Name";
private  static String myPath = DB_PATH + DB_NAME; 
private SQLiteDatabase myDataBase;
private final Context myContext;

public DatabaseHelper(Context context) {
     // TODO Auto-generated constructor stub
    super(context, DB_NAME, null, 1);
    this.myContext=context;
}

public void creatDataBase () throws IOException {
    boolean dbExist = checkDataBase();
    if(dbExist){
        Log.d(LOG_TAG,"DATABASE EXIST");
    }else{
        this.getReadableDatabase();
        copyDataBase();
    }
}

private void copyDataBase() throws IOException {
    // TODO Auto-generated method stub
    InputStream myInput = myContext.getAssets().open(DB_NAME);
    String outFileName = DB_PATH + DB_NAME;
    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();
}

private boolean checkDataBase() {
    // TODO Auto-generated method stub
    File dbFile = new File(DB_PATH + DB_NAME);
    return dbFile.exists();
}

public void openDataBase() throws SQLiteException {
    myDataBase = SQLiteDatabase.openDatabase(myPath,null, SQLiteDatabase.NO_LOCALIZED_COLLATORS);
}

@Override
public synchronized void close() {
    // TODO Auto-generated method stub
    if(myDataBase != null)
    myDataBase.close();
    super.close();
}

score 0 · Accepted Answer · edited May 23 '17 at 12:03

0

Try the sample code here. Find the full working example & follow it.

Code explination & detail can be found here.

edited May 23 '17 at 12:03

Community

1
1

answered Sep 13 '12 at 04:04

Yaqub Ahmad

27,569
23
102
149

score 0 · Answer 3 · edited Sep 23 '12 at 10:48

0

Verify that com.mysoftware.app is the actual name of your app and the file structure and actual database is visible in the DDMS file explorer.

Also, for this example you have to drop your pre-built database into the "assets" folder of your Eclipse project.

edited Sep 23 '12 at 10:48

A.H.

63,967
15
92
126

answered Sep 19 '12 at 17:33

Johnny

1

score 0 · Answer 4 · edited Oct 19 '13 at 10:42

i have dun for that :

public class DatabaseHelper extends SQLiteOpenHelper{

    //The Android's default system path of your application database.
    String DB_PATH =null;

    private static String DB_NAME = "extenalDB";

    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;
        DB_PATH="/data/data/"+context.getPackageName()+"/"+"databases/";
    }   

  /**
     * 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) {

    }
 //return cursor
    public Cursor query(String table,String[] columns, String selection,String[] selectionArgs,String groupBy,String having,String[] orderBy,String youare,String myname, Object object, Object object2, Object object3, Object object4){
        return myDataBase.query("EMP_TABLE", null, null, null, null, null, null, null);


    }


}

Error When I try to open SQLite database pre-created in the assets folder

4 Answers4