database connection in android
<p>Here is the code which I am using as my database helper for my app. I want to enter some values to the db from an activity. How can i do it? and before that I have to check whether the db is connected to my app. Please help me as i am new to android databases.</p>

<pre><code>package com.istyle;

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.istyle/databases/";

    private static String DB_NAME = "istyle.sql";

    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 doesn'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>Here is the activity from which I want to access the database. I am confused about where and how to specify the code to access my db. Please help me. Thanks in advance</p>

<pre><code>package com.istyle;

import java.io.File;
import java.io.IOException;
import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

public class Profile_Page extends Activity {


    private static final int SELECT_PICTURE = 1;
    private String selectedImagePath;
    private ImageView img;
    SQLiteDatabase db;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.profile_page);

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

        try {

            myDbHelper.createDataBase();
            System.out.println("Create db");

    } catch (IOException ioe) {

        throw new Error("Unable to create database");

    }

    try {

        myDbHelper.openDataBase();
        System.out.println("open db");


    }catch(SQLException sqle){

        throw sqle;

    }        

         img = (ImageView)findViewById(R.id.imageView1);
        ((Button) findViewById(R.id.button3))
        .setOnClickListener(new OnClickListener() {
             public void onClick(View arg0) {
                 Intent intent = new Intent();
                 intent.setType("image/*");
                 intent.setAction(Intent.ACTION_GET_CONTENT);


                 startActivityForResult(Intent.createChooser(intent,"Select Picture"), SELECT_PICTURE);

             }
             });    


    }
public void onActivityResult(int requestCode, int resultCode, Intent data) {
                if (resultCode == RESULT_OK) {
                        if (requestCode == SELECT_PICTURE) {
                            Uri selectedImageUri = data.getData();
                            selectedImagePath = getPath(selectedImageUri);
                            System.out.println("Image Path : " + selectedImagePath);
                            img.setImageURI(selectedImageUri);
                        }
                    }
                }

    public String getPath(Uri uri) {
                    String[] projection = { MediaStore.Images.Media.DATA };
                    Cursor cursor = managedQuery(uri, projection, null, null, null);
                    int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
                    cursor.moveToFirst();
                    return cursor.getString(column_index);
                }

}
</code></pre>
