实例教程六：创建数据库与完成数据添删改查--第一种写法

短信小助手（附源码）
http://www.eoeandroid.com/thread-207835-1-1.html

备忘录+SQLite的实现
http://www.eoeandroid.com/thread-208013-1-1.html

音乐波形图
http://www.eoeandroid.com/thread-207796-1-1.html

<?xml version="1.0" encoding="utf-8"?>

 

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

 

    package="cn.itcast.db"

 

    android:versionCode="1"

 

    android:versionName="1.0" >

 



    <uses-sdk android:minSdkVersion="8" />

 



    <application

 

        android:icon="@drawable/ic_launcher"

 

        android:label="@string/app_name" >

 

        <activity

 

            android:name=".MainActivity"

 

            android:label="@string/app_name" >

 

            <intent-filter>

 

                <action android:name="android.intent.action.MAIN" />

 



                <category android:name="android.intent.category.LAUNCHER" />

 

            </intent-filter>

 

        </activity>

 

        <uses-library android:name="android.test.runner"/>

 

    </application>

 



    <instrumentation android:name="android.test.InstrumentationTestRunner"

 

        android:targetPackage="cn.itcast.db" android:label="Tests for My App"></instrumentation>

 

    

</manifest>

package cn.itcast.db;

 



import android.app.Activity;

 

import android.os.Bundle;

 



public class MainActivity extends Activity {

 

    /** Called when the activity is first created. */

 

    @Override

 

    public void onCreate(Bundle savedInstanceState) {

 

        super.onCreate(savedInstanceState);

 

        setContentView(R.layout.main);

 

    }

 

    

    //在Android平台上，集成了一个嵌入式关系型数据库——SQLite

 

    //SQLite3支持NULL、INTEGER、REAL(浮点数字)、TEXT(字符串文本)和BLOB(二进制对象)数据类型

 

    //虽然它支持的类型只有5种，但实际上sqlite3也接受varchar(n)、char(n)、decimal(p, s)等数据

 

    //只不过在运行或保存时会转成对应的五种数据类型

 

    //SQLite最大的特点是你可以把各种类型的数据保存到任何字段中，而不用关心字段声明的数据类型是什么

 

}

package cn.itcast.domain;

 



public class Person {

 

        private Integer id;

 

        private String name;

 

        private String phone;

 

                

        public Person(String name, String phone){

 

                this.name = name;

 

                this.phone = phone;

 

        }

 

        

        public Person(Integer id, String name, String phone){

 

                this.id = id;

 

                this.name = name;

 

                this.phone = phone;

 

        }

 

        

        public Integer getId() {

 

                return id;

 

        }

 

        public void setId(Integer id) {

 

                this.id = id;

 

        }

 

        public String getName() {

 

                return name;

 

        }

 

        public void setName(String name) {

 

                this.name = name;

 

        }

 

        public String getPhone() {

 

                return phone;

 

        }

 

        public void setPhone(String phone) {

 

                this.phone = phone;

 

        }        

}

 

package cn.itcast.service;

 

import android.content.Context;

import android.database.sqlite.SQLiteDatabase;

import android.database.sqlite.SQLiteOpenHelper;

 

public class DBOpenHelper extends SQLiteOpenHelper{

 

        private static final int VERSION = 2; //数据库版本

        

        public DBOpenHelper(Context context){

                 super(context, "itcast.db", null, VERSION); //<包>/database/

 

        }

 

        @Override

 

        public void onCreate(SQLiteDatabase db) { //是在数据库第一次被创建的时候调用的

 

                db.execSQL("CREATE TABLE person(personId integer primary key autoincrement, " + "name varchar(20))");                

        }

 

        @Override

 

        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { //数据库版本号发生改变的时候调用的

                 db.execSQL("ALTER TABLE person ADD phone VARCHAR(12) NULL");

 

        }

 

}

 

package cn.itcast.service;

 



import java.util.ArrayList;

import java.util.List;

import android.content.Context;

import android.database.Cursor;

import android.database.sqlite.SQLiteDatabase;

import cn.itcast.domain.Person;

 

public class PersonService {

 

        private DBOpenHelper dbOpenHelper;      

        public PersonService(Context context){

 

                this.dbOpenHelper = new DBOpenHelper(context); 

        } 

        

        /** 

         * 添加记录 

         * @param person 

         */

 

        public void save(Person person){

 

                SQLiteDatabase db = dbOpenHelper.getWritableDatabase(); 

                db.execSQL("insert into person(name, phone) values(?, ?)",new Object[]{person.getName(), person.getPhone()});

 

                //如果只在一个类中使用db，则不需要关闭，提高性能

                 //但是若是多处使用，则需要关闭

 

//                db.close();

         } 

        

        /**

          * 删除记录 

         * @param id 记录ID 

         */

 

        public void delete(Integer id){

 

                SQLiteDatabase db = dbOpenHelper.getWritableDatabase(); 

                db.execSQL("delete from person where personId=?", new Object[]{id});

 

        }

        

        /**

          * 更新记录

          * @param person

         */

 

        public void update(Person person){

 

                SQLiteDatabase db = dbOpenHelper.getWritableDatabase();

                 db.execSQL("update person set name=?, phone=? where personId=?",

                                 new Object[]{person.getName(), person.getPhone(), person.getId()});

 

        }

         

        /**

         * 查询记录

          * @param id 记录ID

          * @return

          */

 

        public Person find(Integer id){

 

                SQLiteDatabase db = dbOpenHelper.getReadableDatabase();

                 Cursor cursor = db.rawQuery("select * from person where personId=?", new String[]{id.toString()});

 

                if(cursor.moveToFirst()){

 

                        int personId = cursor.getInt(cursor.getColumnIndex("personId")); 

                        String name = cursor.getString(cursor.getColumnIndex("name")); 

                        String phone = cursor.getString(cursor.getColumnIndex("phone")); 

                        return new Person(personId, name, phone); 

                }

 

                cursor.close();               

               return null; 

        }

         

        /**

         * 分布获取记录 

         * @param offset 跳过前面 多少条记录 

         * @param maxResult 每页获取多少条记录 

         * @return 

         */

 

        public List<Person> getScrollData(int offset, int maxResult){

 

                List<Person> persons = new ArrayList<Person>();

 

                SQLiteDatabase db = dbOpenHelper.getReadableDatabase();

                Cursor cursor = db.rawQuery("select * from person order by personId asc limit ?,?", 

                                new String[]{String.valueOf(offset), String.valueOf(maxResult)});

 

                while(cursor.moveToNext()){

 

                        int personId = cursor.getInt(cursor.getColumnIndex("personId"));

                        String name = cursor.getString(cursor.getColumnIndex("name"));

                        String phone = cursor.getString(cursor.getColumnIndex("phone")); 

                        persons.add(new Person(personId, name, phone));

                }

 

                cursor.close();

              return null;

 

        }

 

        

        /**

          * 获取记录总数

         * @return
         */

 

        public long getCount(){

 

                SQLiteDatabase db = dbOpenHelper.getReadableDatabase(); 

                Cursor cursor = db.rawQuery("select count(*) from person", null);

                cursor.moveToFirst();

                long result = cursor.getLong(0);

                cursor.close(); 

                return result;

         }

 }

 

package cn.itcast.test;

 



import java.util.List;

import cn.itcast.domain.Person; 

import cn.itcast.service.DBOpenHelper; 

import cn.itcast.service.PersonService; 

import android.test.AndroidTestCase; 

import android.util.Log;

 



public class PersonServiceTest extends AndroidTestCase{

 

        private static final String TAG = "PersonServiceTest";

 

        public void testCreateDB() throws Exception{

 

                DBOpenHelper dbOpenHelper = new DBOpenHelper(getContext());

                dbOpenHelper.getWritableDatabase(); 

        }        



        public void testSave() throws Exception{

 

                PersonService service = new PersonService(this.getContext()); 

                for(int i = 0; i < 20; i++){

 

                        Person person = new Person("zhangsan", "123456");

                        service.save(person);

                 }

         }

 

        public void testDelete() throws Exception{

 

                PersonService service = new PersonService(this.getContext());

                service.delete(21);

         }

 

        public void testUpdate() throws Exception{

 

                PersonService service = new PersonService(this.getContext());

                Person person = service.find(1);

                person.setName("zhangxiaoxiao");

                service.update(person);

        }

 

        public void testFind() throws Exception{

 

                PersonService service = new PersonService(this.getContext());

                Person person = service.find(1);

                Log.i(TAG, person.toString());

 

        }



        public void testScrollData() throws Exception{

 

                PersonService service = new PersonService(this.getContext());

                List<Person> persons = service.getScrollData(0, 5);

                for(Person person : persons){

                         Log.i(TAG, person.toString());

                 } 

        }

 



        public void testCount() throws Exception{

 

                PersonService service = new PersonService(this.getContext());

                long result = service.getCount();

                 Log.i(TAG, result + "");

         }

 

        //除了execSQL()和rawQuery方法，还提供了对应于添加、删除、更新、查询的操作方法

         //insert(), delete(), update(), query()

 

}