1.数据库帮助类PersonSQLiteOpenHelper
package com.wzw.sqllitedemo.db;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
/**
*
* 数据库帮助类，用于创建管理数据库
* @author Administrator
*
*/
public final class PersonSQLiteOpenHelper extends SQLiteOpenHelper {
private String tag="PersonSQLiteOpenHelper";
/**
* 数据库的构造函数
* @param context
* @param name 数据库名称
* @param factory 游标工厂
* @param version 版本
*/
public PersonSQLiteOpenHelper(Context context) {
super(context, "my.db", null, 1);
}
/**
* 数据库第一次创建时调用此方法
* 用于初始化表
*/
@Override
public void onCreate(SQLiteDatabase db) {
//SQLiteDatabase对象已经连接数据库，直接进行性数据库操作
String sql="create table person(_id integer primary key,name varchar(15),age integer);";
db.execSQL(sql); //创建person表
}
/**
* 数据库的版本号更新时调用
* 用于更新数据库的内容（删除表，更新表，删除表）
*/
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
}
2.实体类person
package com.wzw.sqllitedemo.entities;
public class Person {
private int id;
private int age;
private String name;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Person(int id, int age, String name) {
super();
this.id = id;
this.age = age;
this.name = name;
}
public Person() {
super();
// TODO Auto-generated constructor stub
}
@Override
public String toString() {
return "Person [id=" + id + ", age=" + age + ", name=" + name + "]";
}
}
3.DAO数据库操作类PersonDao
package com.wzw.sqllitedemo.dao;
import java.util.ArrayList;
import java.util.List;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import com.wzw.sqllitedemo.db.PersonSQLiteOpenHelper;
import com.wzw.sqllitedemo.entities.Person;
public class PersonDao {
private PersonSQLiteOpenHelper mOpenHelper;
/**
*构造函数，谁调用需要传递一个context上下文对象
* @param context
*/
public PersonDao(Context context){
mOpenHelper = new PersonSQLiteOpenHelper(context);
}
/**
* 添加person表一条数据
* @param person
*/
public void insert(Person person){
SQLiteDatabase db=mOpenHelper.getWritableDatabase();
if(db.isOpen()){//如果数据库打开，则进行插入操作
//String sql="insert into person(name,age) values('李四',18);";
db.execSQL("insert into person(name,age) values(?,?);", new Object[]{person.getName(),person.getAge()});
db.close();
}
}
public void delete(int id){
SQLiteDatabase db=mOpenHelper.getWritableDatabase();//获取可写的数据库对象
if(db.isOpen()){//如果数据库打开，则进行插入操作
db.execSQL("delete from person where _id=?", new Integer[]{id});
db.close();
}
}
public void update(int id,String name){
SQLiteDatabase db=mOpenHelper.getWritableDatabase();
if(db.isOpen()){//如果数据库打开，则进行插入操作
db.execSQL("update person set name=? where _id=?", new Object[]{name,id});
db.close();
}
}
public List<Person> queryAll(){
SQLiteDatabase db=mOpenHelper.getReadableDatabase();//获得只读数据库对象
if(db.isOpen()){
Cursor cursor=db.rawQuery("select _id,name,age from person", null);
if(cursor.getCount()>0 && cursor!=null){
List<Person> personList=new ArrayList<Person>();
int id;
String name;
int age;
while(cursor.moveToNext()){
id=cursor.getInt(0);//取第0列的ID
name=cursor.getString(1);//取第1列的name
age=cursor.getInt(2);//取第2列的age
personList.add(new Person(id, age, name));
}
db.close();
return personList;
}
db.close();
}
return null;
}
public Person queryItem(int id){
SQLiteDatabase db=mOpenHelper.getReadableDatabase();
if(db.isOpen()){
Cursor cursor=db.rawQuery("select _id,name,age from person where id=?", new String[]{id+""});
if(cursor!=null && cursor.moveToFirst()){
int _id=cursor.getInt(0);
String name=cursor.getString(1);
int age=cursor.getInt(2);
db.close();
return new Person(_id, age, name);
}
db.close();
}
return null;
}
}
4.测试类
package com.wzw.sqllitedemo.test;
import java.util.List;
import com.wzw.sqllitedemo.dao.PersonDao;
import com.wzw.sqllitedemo.db.PersonSQLiteOpenHelper;
import com.wzw.sqllitedemo.entities.Person;
import android.database.sqlite.SQLiteDatabase;
import android.test.AndroidTestCase;
import android.util.Log;
public class TestCase extends AndroidTestCase {
private String tag="TestCase";
public void test(){
//数据库什么时候创建
PersonSQLiteOpenHelper openHelp=new PersonSQLiteOpenHelper(getContext());
//第一次连接数据库的时创建数据库，oncreate调用
openHelp.getWritableDatabase();
}
public void testinsert(){
PersonDao dao=new PersonDao(getContext());
Person person=new Person(0,67,"zhang");
dao.insert(person);
}
public void testDelete(){
PersonDao dao=new PersonDao(getContext());
dao.delete(1);
}
public void testUpdate(){
PersonDao dao=new PersonDao(getContext());
dao.update(2, "你妹");
}
public void testQueryAll(){
PersonDao dao=new PersonDao(getContext());
List<Person> personList=dao.queryAll();
for (Person person : personList) {
Log.i(tag,person.toString());
}
}
public void testQueryItem(){
PersonDao dao=new PersonDao(getContext());
Person person=dao.queryItem(1);
Log.i(tag, person.toString());
}
}
需要在AndroidManifest.xml文件中声明测试
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.wzw.sqllitedemo"
android:versionCode="1"
android:versionName="1.0" >
<span style="color:#ff6666;"><instrumentation android:name="android.test.InstrumentationTestRunner" android:targetPackage="com.wzw.sqllitedemo"></instrumentation></span>
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<span style="color:#ff0000;"><uses-library android:name="android.test.runner"/></span>
<activity
android:name="com.wzw.sqllitedemo.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>
android中SQLite数据库的增删改查,布布扣,bubuko.com
时间： 2024-10-14 03:34:17