安卓视频开发 mysql_在Android应用中使用SQLite数据库（传智播客视频笔记）

在Android应用中使用SQLite数据库

应用生成的数据库文件保存为/data/data/应用包名/databases/name.db，生成的文件可用SQLite Expert打开

(name是自定义的，例如，我的应用是保存在：/data/data/com.sinaapp.sql/databases/ssun.db中)

SQLiteActivity.java源码：

package com.sinaapp.sql;

import com.sinaapp.sql.R;

import android.app.Activity;

import android.os.Bundle;

public class SQLiteActivity extends Activity {

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

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

}

Pseron.java源码：

package com.sinaapp.domain;

public class Person {

private String name;

private Integer id;

private String phone;

private Integer amount;

public Person() {}

@Override

public String toString() {

return "Person [name=" + name + ", id=" + id + ", phone=" + phone

+ ", amount=" + amount + "]";

}

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

this.name = name;

this.id = id;

this.phone = phone;

this.amount = amount;

}

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

this.name = name;

this.phone = phone;

this.amount = amount;

}

public Integer getAmount() {

return amount;

}

public void setAmount(Integer amount) {

this.amount = amount;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public Integer getId() {

return id;

}

public void setId(Integer id) {

this.id = id;

}

public String getPhone() {

return phone;

}

public void setPhone(String phone) {

this.phone = phone;

}

DBOpenHelper.java源码：

package com.sinaapp.service;

import android.content.Context;

import android.database.sqlite.SQLiteDatabase;

import android.database.sqlite.SQLiteOpenHelper;

public class DBOpenHelper extends SQLiteOpenHelper {

public DBOpenHelper(Context context) {

super(context, "ssun.db", null, 3);//数据库版本号改变，将会执行onUpgrade方法

}

@Override

public void onCreate(SQLiteDatabase db) {//第一次使用时执行的方法

// TODO Auto-generated method stub

db.execSQL("create table person(id integer primary key autoincrement,name varchar(20),phone varchar(20))");

}

@Override

public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

// TODO Auto-generated method stub

db.execSQL("alter table person add amount int(10)");

}

PersonService.java源码：

package com.sinaapp.service;

import java.util.ArrayList;

import java.util.List;

import android.content.Context;

import android.database.Cursor;

import android.database.sqlite.SQLiteDatabase;

import com.sinaapp.domain.Person;

public class PersonService {

private DBOpenHelper helper;

public PersonService(Context context){

this.helper = new DBOpenHelper(context);

}

public void payment(){

SQLiteDatabase db = helper.getWritableDatabase();

try{

db.beginTransaction();

db.execSQL("update person set amount = amount - 10 where id = 3");

db.execSQL("update person set amount = amount + 10 where id = 4");

db.setTransactionSuccessful();

}finally{

db.endTransaction();

}

/**

* 添加记录

* @param person

public void add(Person person){

SQLiteDatabase db = helper.getWritableDatabase();

db.execSQL("insert into person(name,phone,amount) values(?,?,?) ",

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

}

/**

* 删除记录

* @param integer 将要删除的记录的ID号

public void delete(Integer integer){

SQLiteDatabase db = helper.getWritableDatabase();

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

}

/**

* 更新记录

* @param person 更新的记录

public void update(Person person){

SQLiteDatabase db = helper.getWritableDatabase();

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

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

}

/**

* 查找记录

* @param integer

* @return

public Person find(Integer integer){

Person person = null;

SQLiteDatabase db = helper.getWritableDatabase();

Cursor cursor = db.rawQuery("select * from person where id = ?",

new String[]{integer.toString()});

if(cursor.moveToFirst()){

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

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

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

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

person = new Person(name,id,phone,amount);

}

return person;

}

/**

* 分页显示记录

* @param start 开始记录号

* @param length 记录长度

* @return

public List getPersons(Integer start, Integer length){

List persons = new ArrayList();

Person person = null;

SQLiteDatabase db = helper.getWritableDatabase();

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

new String[]{start.toString(),length.toString()});

while(cursor.moveToNext()){

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

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

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

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

person = new Person(name,id,phone,amount);

persons.add(person);

person = null;

}

cursor.close();

return persons;

}

/**

* 得到记录数

* @return

public Integer getCounts(){

SQLiteDatabase db = helper.getWritableDatabase();

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

cursor.moveToFirst();

Integer counts = cursor.getInt(0);

return counts;

}

单元测试TestService.java源码：

package com.sinaapp.test;

import java.util.List;

import android.test.AndroidTestCase;

import android.util.Log;

import com.sinaapp.domain.Person;

import com.sinaapp.service.DBOpenHelper;

import com.sinaapp.service.PersonService;

public class TestService extends AndroidTestCase {

public void testCreateDB() {

DBOpenHelper helper = new DBOpenHelper(this.getContext());

helper.getWritableDatabase();

}

public void testAdd(){