Android(安卓)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）

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