public class DatabaseHelper extends SQLiteOpenHelper {
private static final String DATABASE_NAME="upgrade";
private static final int DATABASE_VERSION=2;

//details table details
public static final String TABLE_NAME_Details="details";
public static final String USERNAME="USERNAME";
public static final String PASSWORD="PASSWORD";
public static final String Name="Name"; //newly added column in version 2

//create table statements for version 2
public static final String Create_Table_Details = "CREATE TABLE "
        + TABLE_NAME_Details + " (" + USERNAME + " TEXT PRIMARY KEY,"
        + PASSWORD + " TEXT ,"
        + Name + " TEXT"
        +")";

 /*   creation for version 1
private static final String Create_Table_Details = "CREATE TABLE " + TABLE_NAME_Details + "("
        + USERNAME + " TEXT PRIMARY KEY,"
        + PASSWORD + " TEXT"
        + ")";*/


//Alter table statements FOR onUpgrade()
private static final String ALTER_Details = "ALTER TABLE" + TABLE_NAME_Details + "ADD COLUMN" + Name + "TEXT";

public DatabaseHelper(Context context)
{
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
}

@Override
public void onCreate(SQLiteDatabase db) {
    try{
        db.execSQL(Create_Table_Details);
        Log.d("database","installed successfully");

    }catch (Exception e)
    {
        e.printStackTrace();
        Log.e("/test","Exception due to"+e.toString());
    }

}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion){
    try{
        Log.d("eEmp/DBUpgrade", "oldVersion:" + oldVersion + ", NewVersion:" + newVersion);
   /* db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME_Details);
    onCreate(db);*/

        if(oldVersion < 2)
        {
            try{
                Cursor c = db.rawQuery("Select * from " + TABLE_NAME_Details + " WHERE 1 = 0", null);
                if (c.getColumnIndex(Name) == -1) {
                    db.execSQL(ALTER_Details);
                }
                if (c != null)
                    c.close();
            }catch(Exception upgradeexp)
            {
                upgradeexp.printStackTrace();
                Log.e("/test","Exception due to" + upgradeexp.toString());
            }
        }

    }catch(Exception dbUpgradeExp)
    {
        dbUpgradeExp.printStackTrace();
        Log.e("/test","Exception due to" + dbUpgradeExp.toString());
    }
   /* if(oldVersion < 2)
    {
        db.execSQL(ALTER_Details);
    }*/

}

//inserting login data to database
public boolean insertData(String username, String password,String name)
{
    try{
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues contentValues=new ContentValues();

        contentValues.put(USERNAME,username);
        contentValues.put(PASSWORD,password);
        contentValues.put(Name,name);
        long result=db.insert(TABLE_NAME_Details, null, contentValues);
        if(result==-1)
            return false;
        else
            return true;
    }catch(Exception e)
    {
        e.printStackTrace();
        Log.e("/test","Exception due to"+e.toString());
        return false;
    }
}

//getting data from database
public Cursor getAllData()
{
    SQLiteDatabase db = this.getWritableDatabase();
    Cursor res = db.rawQuery("select * from "+TABLE_NAME_Details,null);
    return res;
}

}