Java:
import java.util.ArrayList;

import android.app.Activity;
import android.database.Cursor;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class DatabaseActivity extends Activity
{
	ArrayList<String> results = new ArrayList<String>();

	private EditText etUsername;
	private Button btnLogin;
	DBAdapter db = new DBAdapter(this);

    @Override

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

        etUsername = (EditText)findViewById(R.id.usernametxt);
        btnLogin = (Button)findViewById(R.id.btnLogin);

        db.open();
        db.insertTitle("mani","mani");
        db.insertTitle("sudhakar","sudhakar");
        db.close();


        btnLogin.setOnClickListener(new OnClickListener() {
        @Override
       	 public void onClick(View v) {
        	String username = etUsername.getText().toString();

            db.open();

            Cursor c = db.getTitles(username);
            if  (c.moveToFirst()) {
    			do {
    				String firstName = c.getString(1);
    				String lastname = c.getString(2);
    				results.add("Firstname" + firstName + "Lastname: " + lastname);
    			}while (c.moveToNext());
    		}

         Toast.makeText(DatabaseActivity.this, (CharSequence) results,Toast.LENGTH_SHORT).show();

            db.close();

        }
        });
    }


}


DBAdapter:

package com.database.demo.user;


import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;


public class DBAdapter
{
	public static final String KEY_ROWID = "_id";
    public static final String KEY_USER = "user";
    public static final String KEY_PASS = "pass";
    private static final String TAG = "DBAdapter";

    private static final String DATABASE_NAME = "login";
    private static final String DATABASE_TABLE = "userpass";
    private static final int DATABASE_VERSION = 1;

    private static final String DATABASE_CREATE =
        "create table userpass (_id integer primary key autoincrement, "
        + "user text not null, pass text not null); ";


    private final Context context;

    private DatabaseHelper DBHelper;
    private SQLiteDatabase db;

    public DBAdapter(Context ctx)
    {
        this.context = ctx;
        DBHelper = new DatabaseHelper(context);
    }

    private static class DatabaseHelper extends SQLiteOpenHelper
    {
        DatabaseHelper(Context context)
        {
            super(context, DATABASE_NAME, null, DATABASE_VERSION);
        }



        @Override
        public void onCreate(SQLiteDatabase db)
        {
            db.execSQL(DATABASE_CREATE);
        }



        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion,
                              int newVersion)
        {
            Log.w(TAG, "Upgrading database from version " + oldVersion
                  + " to "
                  + newVersion + ", which will destroy all old data");
            db.execSQL("DROP TABLE IF EXISTS titles");
            onCreate(db);
        }

    }
        //---opens the database---
        public DBAdapter open() throws SQLException
        {
            db = DBHelper.getWritableDatabase();
            return this;
        }

      //---closes the database---
        public void close()
        {
            DBHelper.close();
        }

        //---insert a title into the database---
        public long insertTitle(String user, String pass)
        {
            ContentValues initialValues = new ContentValues();
            initialValues.put(KEY_USER, user);
            initialValues.put(KEY_PASS, pass);
            return db.insert(DATABASE_TABLE, null, initialValues);
        }

      //---deletes a particular title---
        public boolean deleteTitle(long rowId)
        {
            return db.delete(DATABASE_TABLE, KEY_ROWID +
            		"=" + rowId, null) > 0;
        }

        //---retrieves all the titles---
        public Cursor getAllTitles()
        {
            return db.query(DATABASE_TABLE, new String[] {
            		KEY_ROWID,
            		KEY_USER,
            		KEY_PASS},
                    null,
                    null,
                    null,
                    null,
                    null);
        }

         public Cursor getTitles(String searchValue)
         {
        	 return db.rawQuery( "SELECT * FROM "+DATABASE_TABLE +" WHERE user LIKE '%"+searchValue+"%'", null);

         }

            //---retrieves a particular title---
            public Cursor getTitle(long rowId) throws SQLException
            {
                Cursor mCursor =
                        db.query(true, DATABASE_TABLE, new String[] {
                        		KEY_ROWID,
                        		KEY_USER,
                        		KEY_PASS,

                        		},
                        		KEY_ROWID + "=" + rowId,
                        		null,
                        		null,
                        		null,
                        		null,
                        		null);
                if (mCursor != null) {
                    mCursor.moveToFirst();
                }
                return mCursor;
            }


        //---updates a title---
        public boolean updateTitle(long rowId, String isbn,
        String title, String publisher)
        {
            ContentValues args = new ContentValues();
            args.put(KEY_USER, isbn);
            args.put(KEY_PASS, title);

            return db.update(DATABASE_TABLE, args,
                             KEY_ROWID + "=" + rowId, null) > 0;
        }

    }