title: How to access and query the database that is copied to the assets folder?
body: <p>I have read few tutorials where in a pre-existing database is copied to assets folder and write code for copying this database on to the default system path of the application database. </p>
  
  <pre><code>package com.example.c1;
  
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  
  import android.content.Context;
  import android.database.Cursor;
  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.c/databases/";
  
          private static String DB_NAME = "MyDatabase";
  
          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))&gt;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.
  
  }
  </code></pre>
  
  <p>I use this code for copying the database from assets folder to default path. </p>
  
  <pre><code>package com.example.c1;
  
  import java.io.IOException;
  import com.example.c1.DataBaseHelper;
  import android.os.Bundle;
  import android.app.Activity;
  import android.database.SQLException;
  import android.view.Menu;
  import android.widget.TextView;
  
  public class C1 extends Activity {
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.c1);
  
          DataBaseHelper 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;
  
           }
  
  
      }
  
      @Override
      public boolean onCreateOptionsMenu(Menu menu) {
          // Inflate the menu; this adds items to the action bar if it is present.
          getMenuInflater().inflate(R.menu.c1, menu);
          return true;
      }
  
  }
  </code></pre>
  
  <p>Running this, the emulator says c1 has stopped. I click on the DDMS view and in file explorer I choose my package. I found "databases" folder. My database in the assets folder ie; "MyDatabase" is found here. But when I pull the file and open it in sqlite browser it only shows the android_metadata table but doesn't show other tables in my database. I am also not able to execute any query. How can I access and query the database? like executing a "Select" statement in DataBaseHelper class and showing the result of it. I hope am clear with my problem. I have a database copied on to assets folder and a code to copy this database to the default path. Is the code correct? If not then what is the correction I should make? I need to execute query n how to do it??</p>