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  • 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)

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  • 原文地址:https://www.cnblogs.com/Joanna-Yan/p/4942707.html
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