Android 数据库框架OrmLite的使用（一）

在这里记录下最基本的用法，官网上可了解相关的介绍。

1、下载OrmLite jar

　　在下载android的:ormlite-android-4.48.jar和ormlite-core-4.48.jar，放在你项目的libs目录下。

2、编写Bean类

package com.example.ormlite.bean;

import java.util.Collection;

import com.j256.ormlite.field.DatabaseField;
import com.j256.ormlite.field.ForeignCollectionField;
import com.j256.ormlite.table.DatabaseTable;

@DatabaseTable(tableName="tb_user")  //表明这是数据库中的一张表
public class User {
    @DatabaseField(generatedId=true)  //generatedId表示id为主键切自动生成
    private int id;
    @DatabaseField(columnName="name")  //columnName的值为该字段在数据库表中的列名
    private String name;
    @DatabaseField(columnName="desc")
    private String desc;

    public User() {

    }
    public User(String name, String desc) {
        this.name = name;
        this.desc = desc;
    }
    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 getDesc() {
        return desc;
    }
    public void setDesc(String desc) {
        this.desc = desc;
    }
    @Override
    public String toString() {
        return "User [id=" + id + ", name=" + name + ", desc=" + desc + "]";
    }
}

3.编写Dao类

package com.example.ormlite.db;

import java.sql.SQLException;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;

import com.example.ormlite.bean.User;
import com.j256.ormlite.android.apptools.OrmLiteSqliteOpenHelper;
import com.j256.ormlite.dao.Dao;
import com.j256.ormlite.support.ConnectionSource;
import com.j256.ormlite.table.TableUtils;
/**
 * 编写DAO类
 * 原生的数据库操作，需要继承SQLiteOpenHelper,这里我们需要继承OrmLiteSqliteOpenHelper（间接继承了SQLiteOpenHelper）
 * @author Administrator
 *
 */
public class DatabaseHelper extends OrmLiteSqliteOpenHelper{
    private static final String TABLE_NAME="sqlite-test.db";
    private static DatabaseHelper instance;

    //userDao,每张表对应一个
    private Dao<User,Integer> userDao;
    public DatabaseHelper(Context context) {
        super(context, TABLE_NAME, null, 2);
    }

    /**
     * 建表
     */
    @Override
    public void onCreate(SQLiteDatabase database, ConnectionSource connectionSource) {
        try {
            TableUtils.createTable(connectionSource, User.class);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    /**
     * 更新表
     */
    @Override
    public void onUpgrade(SQLiteDatabase database, ConnectionSource connectionSource, int oldVersion,
            int newVersion) {
        try {
            TableUtils.dropTable(connectionSource, User.class, true);
            onCreate(database, connectionSource);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    /**
     * 单例获取该Helper
     * @param context
     * @return
     */
    public static synchronized DatabaseHelper getHelper(Context context){
        if(instance==null){
            synchronized(DatabaseHelper.class){
                if(instance==null){
                    instance=new DatabaseHelper(context);
                }
            }
        }
        return instance;
    }

    /**
     * 获得userDao
     * 我们会有很多表，每个表一般我们都会单独写个Dao用于操作，这里为了简单我并没有抽取出来，直接写在helper中，比如UserDao的获取
     * @return
     * @throws SQLException
     */
    public Dao<User,Integer> getUserDao() throws SQLException{
        if(userDao==null){
            userDao=getDao(User.class);
        }
        return userDao;
    }

    /**
     * 释放资源
     */
    @Override
    public void close() {
        super.close();
        userDao=null;
    }
}

4.测试

关于单元测试的配置可参考Android Junit测试框架

package com.example.ormlite.test;

import java.sql.SQLException;
import java.util.List;

import android.test.AndroidTestCase;
import android.util.Log;

import com.example.ormlite.bean.User;
import com.example.ormlite.dao.UserDao;
import com.example.ormlite.db.DatabaseHelper;

public class OrmLiteDbTest extends AndroidTestCase{
    public void testAddUser(){
//        User u1=new User("yanqiong", "developer");
//        DatabaseHelper helper=DatabaseHelper.getHelper(getContext());
//        try {
//            helper.getUserDao().create(u1);
//            u1=new User("yanqiong2", "developer");
//            helper.getUserDao().create(u1);
//            u1=new User("yanqiong3", "developer");
//            helper.getUserDao().create(u1);
//            u1=new User("yanqiong4", "developer");
//            helper.getUserDao().create(u1);
//
//            testList();
//        } catch (SQLException e) {
//            e.printStackTrace();
//        }

        User u1=new User("yanqiong5", "developer");
        UserDao userDao=new UserDao(getContext());
        userDao.add(u1);

    }

    public void testList() {
        DatabaseHelper helper=DatabaseHelper.getHelper(getContext());
        User u1=new User("yanqiong-android", "developer");
        u1.setId(2);
        List<User> users;
        try {
            users = helper.getUserDao().queryForAll();
            Log.i("OrmLiteDbTest", users.toString());
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public void testDeleteUser(){
        DatabaseHelper helper=DatabaseHelper.getHelper(getContext());
        try {
            helper.getUserDao().deleteById(2);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public void testUpdateUser(){
        DatabaseHelper helper=DatabaseHelper.getHelper(getContext());
        User u1=new User("yanqiong-android", "developer");
        u1.setId(3);
        try {
            helper.getUserDao().update(u1);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

规范的写法请参考Android 数据库框架OrmLite的使用（二）