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<Person> getPersons(Integer start, Integer length){
List<Person> persons = new ArrayList<Person>();
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(){
PersonService service = new PersonService(this.getContext());
service.add(new Person("luolin","12345",100));
}

public void testUpdate(){
PersonService service = new PersonService(this.getContext());
service.update(new Person("zhang",4,"2222222",200));
}

public void testFind(){
PersonService service = new PersonService(this.getContext());
Person person = service.find(1);
Log.i("TestService", person.toString());
}

public void testDel(){
PersonService service = new PersonService(this.getContext());
service.delete(2);
}

public void testGetCounts(){
PersonService service = new PersonService(this.getContext());
Integer i = service.getCounts();
Log.i("TestService", i.toString());
}

public void testGetPersons(){
PersonService service = new PersonService(this.getContext());
List<Person> persons = service.getPersons(0, 4);
for(Person p : persons){
Log.i("TestService", p.toString());
}
}

public void testPayment(){
PersonService service = new PersonService(this.getContext());
service.payment();
}
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.sinaapp.sql"
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=".SQLiteActivity"
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="com.sinaapp.sql" />

</manifest>