public void Transaction(){
  SQLiteDatabase database=db.getReadableDatabase();
  database.beginTransaction(); //开启事务
  try{
   String sql1="update student set username='lili' where userid=2";
   String sql2="update student set username='lucy' where userid=3";
   database.execSQL(sql1);
   database.execSQL(sql2);
   database.setTransactionSuccessful(); //设置事务的状态，这句不写事务就会回滚
  }finally{
    database.endTransaction(); //结束事务
  }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  >
<LinearLayout
 xmlns:android="http://schemas.android.com/apk/res/android"
 android:orientation="horizontal"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content">
 <TextView
  android:layout_width="60dip"
  android:layout_height="wrap_content"
  android:text="用户id"
 />
  <TextView
  android:layout_width="60dip"
  android:layout_height="wrap_content"
   android:text="用户名"
 />
  <TextView
  android:layout_width="60dip"
  android:layout_height="wrap_content"
  android:text="用户住址"
 />
</LinearLayout>
  <ListView
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:id="@+id/listview"
  />
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
 xmlns:android="http://schemas.android.com/apk/res/android"
 android:orientation="horizontal"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content">
 <TextView
  android:layout_width="60dip"
  android:layout_height="wrap_content"
  android:id="@+id/userid"
 />
  <TextView
  android:layout_width="60dip"
  android:layout_height="wrap_content"
  android:id="@+id/username"
 />
  <TextView
  android:layout_width="90dip"
  android:layout_height="wrap_content"
  android:id="@+id/address"
 />
</LinearLayout>

package org.lxh.db;
import java.util.*;
import org.lxh.service.StudentService;
import org.lxh.vo.Student;
import android.app.Activity;
import android.database.Cursor;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.SimpleCursorAdapter;
import android.widget.Toast;
public class DBActivity extends Activity {
  private StudentService service;
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    this.service=new StudentService(this);
    ListView view=(ListView)this.findViewById(R.id.listview);
    List<Student> all=this.service.fiandAll();
    List<HashMap<String,Object>> data=new ArrayList<HashMap<String,Object>>();
    //逐个取出元素
    Iterator<Student> it=all.iterator();
    Student stu=null;
    while(it.hasNext()){
      stu=new Student();
      stu=it.next();
      HashMap<String,Object> map=new HashMap<String,Object>();
      map.put("userid", stu.getUserid());
      map.put("username", stu.getUsername());
      map.put("address", stu.getAddress());
      data.add(map);
    }
    //数据绑定
    SimpleAdapter adapter=new SimpleAdapter(this, data, R.layout.listview, new String[]{"userid","username","address"},new int[]{R.id.userid,R.id.username,R.id.address});
    view.setAdapter(adapter);
    //添加列表项监听事件
    view.setOnItemClickListener(new OnItemClickListener(){
      public void onItemClick(AdapterView<?> parent, View view,int position, long id) {
        ListView listview=(ListView)parent;
        HashMap<String,Object> hash=(HashMap<String,Object>)listview.getItemAtPosition(position);
        Toast.makeText(DBActivity.this, hash.get("userid").toString(), 1).show();
      }});
}

HashMap<String,Object> map=new HashMap<String,Object>();

List<HashMap<String,Object>> data=new ArrayList<HashMap<String,Object>>();

SimpleAdapter adapter=new SimpleAdapter(this, data, R.layout.listview, new String[]{"userid","username","address"},new int[]{R.id.userid,R.id.username,R.id.address});
    view.setAdapter(adapter);

public List<Student> fiandAll(){
  List<Student> all=new ArrayList<Student>();
  String sql="select * from student";
  SQLiteDatabase database=db.getReadableDatabase(); //使用getReadableDatabase取得SQLiteDatabase
  Cursor cursor=database.rawQuery(sql, null); //得到游标,类似resultset
  Student stu;
  while(cursor.moveToNext()){ //移动游标
    int id=cursor.getInt(cursor.getColumnIndex("userid"));
    String name=cursor.getString(cursor.getColumnIndex("username"));
    String address=cursor.getString(cursor.getColumnIndex("address"));
    stu=new Student();
    stu.setUserid(id);
    stu.setUsername(name);
    stu.setAddress(address);
    all.add(stu);
  }
  cursor.close(); //关闭游标
  return all;
}

public Cursor fiandAllCursor(){
  List<Student> all=new ArrayList<Student>();
  String sql="select userid as _id,username,address from student";
  SQLiteDatabase database=db.getReadableDatabase(); //使用getReadableDatabase取得SQLiteDatabase
  Cursor cursor=database.rawQuery(sql, null); //得到游标,类似resultset
  //cursor.close(); //这里不可以关闭游标
  return cursor;
}

Cursor all=this.service.fiandAllCursor(); //使用游标适配器
SimpleCursorAdapter cadapter=new SimpleCursorAdapter(this, R.layout.listview,all, new String[]{"_id","username","address"},new int[]{R.id.userid,R.id.username,R.id.address});
view.setAdapter(cadapter);
//添加列表项监听事件
view.setOnItemClickListener(new OnItemClickListener(){
public void onItemClick(AdapterView<?> parent, View view,int position, long id) {
  ListView listview=(ListView)parent;
  Cursor hash=(Cursor)listview.getItemAtPosition(position); //取得被点击item的位置
  int temp=hash.getInt(hash.getColumnIndex("_id"));
  Toast.makeText(DBActivity.this, String.valueOf(temp), 1).show();
}});