Android实现SQLite数据库的增、删、改、查的操作

核心代码DAO类

package com.examp.use_SQLite.dao;import java.util.ArrayList;import java.util.List;import android.content.ContentValues;import android.content.Context;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import com.examp.use_SQLite.PersonSQLiteOpenHelper;import com.examp.use_SQLite.domain.Person;public class PersonDao {// 获取要操作的数据库对象private PersonSQLiteOpenHelper helper;/** * 在构造方法中完成helper的初始化 *  * @param context */public PersonDao(Context context) {helper = new PersonSQLiteOpenHelper(context);}/** * 添加数据 *  * @param name姓名 * @param number电话 */public void add(String name, String number) {// 获取数据库的连接对象SQLiteDatabase db = helper.getWritableDatabase();// 执行一条SQL语句,并不是一个查询/插入/更新/删除。　　// db.execSQL("insert into person (name,number) values (?,?)",// new Object[] { name, number });// 下面是API推荐的写法ContentValues values = new ContentValues();values.put("name", name);values.put("number", number);db.insert("person", null, values);// 及时的关闭数据库连接db.close();}/** * 根据用户姓名查询数据 *  * @param name *            查询条件 * @return 查询结果 */public Person findByName(String name) {// 获取数据库连接SQLiteDatabase db = helper.getReadableDatabase();// 执行数据库操作语句,// 得到游标Cursor实例,也就是结果集,类似于Javaweb中的ResultSetCursor cursor = db.rawQuery("select * from person where name=?",new String[] { name });// 声明结果对象Person person = null;// 判断是否有结果返回if (cursor.moveToNext()) {// 取出数据集中的单行数据的个字段的数据// cursor.getColumnIndex("id");获取指定的字段的下标// cursor.getInt(index);或getString(index);是获取指定的下标的数据index为int类型;int id = cursor.getInt(cursor.getColumnIndex("id"));String named = cursor.getString(cursor.getColumnIndex("name"));String number = cursor.getString(cursor.getColumnIndex("number"));// 实例化查询结果数据对象person = new Person(id, named, number);}// 关闭数据库连接,释放资源db.close();// 返回数据结果对象return person;}/** * 根据name更新一条数据 *  * @param name *            跟新条件 * @param newnumber *            新的数据 */public void update(String name, String newnumber) {SQLiteDatabase db = helper.getWritableDatabase();db.execSQL("update person set number=? where name=?", new Object[] {newnumber, name });db.close();}/** * 根据指定的名字删除数据 *  * @param name *            删除条件 *  */public void delete(String name) {SQLiteDatabase db = helper.getWritableDatabase();db.execSQL("delete from person where name=?", new Object[] { name });db.close();}public List<Person> findAll() {SQLiteDatabase db = helper.getReadableDatabase();Cursor cursor = db.rawQuery("select * from person", null);// 声明结果集// 初始化结果集List<Person> persons = new ArrayList<Person>();// 判断是否有结果返回while (cursor.moveToNext()) {// 声明结果对象Person person = null;// 取出数据集中的单行数据的个字段的数据// cursor.getColumnIndex("id");获取指定的字段的下标// cursor.getInt(index);或getString(index);是获取指定的下标的数据index为int类型;int id = cursor.getInt(cursor.getColumnIndex("id"));String named = cursor.getString(cursor.getColumnIndex("name"));String number = cursor.getString(cursor.getColumnIndex("number"));// 实例化查询结果数据对象person = new Person(id, named, number);// 向结果集中添加数据persons.add(person);}// 关闭连接,释放资源db.close();// 放回结果集return persons;}}

用到的其它的辅助类

package com.examp.use_SQLite;import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteOpenHelper;/** * 数据库创建的类 *  * @author MartinDong *  */public class PersonSQLiteOpenHelper extends SQLiteOpenHelper {/** * 数据库的构造方法,用来定义:数据库的环境、数据库的名称、数据库查询结果及、数据库版本 *  * @param context */public PersonSQLiteOpenHelper(Context context) {super(context, "person.db", null, 1);}/** * 在数据库第一次被创建的时候调用的方法 *  * @param db被创建的数据库 */@Overridepublic void onCreate(SQLiteDatabase db) {// 初始化数据库的表结构db.execSQL("create table person (id integer primary key autoincrement,name varchar(20),number varchar(20))");}@Overridepublic void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {}}

实体业务Bean

package com.examp.use_SQLite.domain;public class Person {private int id;private String name;private String number;public Person() {}public Person(int id, String name, String number) {this.id = id;this.name = name;this.number = number;}public int getId() {return id;}public void setId(int id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getNumber() {return number;}public void setNumber(String number) {this.number = number;}@Overridepublic String toString() {return "Person [id=" + id + ", name=" + name + ", number=" + number+ "]";}}

测试类

package com.examp.use_SQLite.test;import java.util.List;import com.examp.use_SQLite.PersonSQLiteOpenHelper;import com.examp.use_SQLite.dao.PersonDao;import com.examp.use_SQLite.domain.Person;import android.test.AndroidTestCase;public class TestPerson extends AndroidTestCase {public void testCreateDB() throws Exception {PersonSQLiteOpenHelper helper = new PersonSQLiteOpenHelper(getContext());helper.getWritableDatabase();}public void testAdd() {PersonDao dao = new PersonDao(getContext());dao.add("donghongyu", "1231231");}public void testFindByname() {PersonDao dao = new PersonDao(getContext());Person person = dao.findByName("lisi");System.out.println(person.toString());}public void testUpdate() {PersonDao dao = new PersonDao(getContext());dao.update("lisi", "11111111111");}public void testDelete() {PersonDao dao = new PersonDao(getContext());dao.delete("lisi");}public void testFindAll() {PersonDao dao = new PersonDao(getContext());List<Person> persons = dao.findAll();for (Person person : persons) {System.out.println(person);}}}

注意：使用Junit进行测试的时候，权限文件    AndroidManifest.xml中需要添加如下的设置

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.examp.use_SQLite"    android:versionCode="1"    android:versionName="1.0" >    <instrumentation        android:name="android.test.InstrumentationTestRunner"        android:targetPackage="com.examp.use_SQLite" />    <uses-sdk        android:minSdkVersion="8"        android:targetSdkVersion="18" />    <application        android:allowBackup="true"        android:icon="@drawable/ic_launcher"        android:label="@string/app_name"        android:theme="@style/AppTheme" >        <uses-library android:name="android.test.runner" />        <activity            android:name="com.examp.use_SQLite.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>    </application></manifest>