Android数据库框架ORMLite

转载出处：http://blog.csdn.net/lmj623565791/article/details/39121377

大家在Android项目中或多或少的都会使用数据库，为了提高我们的开发效率，当然少不了数据库ORM框架了，尤其是某些数据库操作特别频繁的app；本篇博客将详细介绍ORMLite的简易用法。

使用方法：

1、下载ORMLite的jar包：对于Android为：ormlite-android-4.48.jar 和 ormlite-core-4.48.jar ；

2、有了jar包就可以开始配置Bean类了

package db;import com.j256.ormlite.field.DatabaseField;import com.j256.ormlite.table.DatabaseTable;/** * Created by wls on 2016/10/4. */@DatabaseTable(tableName = "tb_student")public class Student {    @DatabaseField(generatedId = true)    private int id;    @DatabaseField(columnDefinition = "name")    private String name;    @DatabaseField(columnDefinition = "sex")    private String sex;    @DatabaseField(columnDefinition = "address")    private String address;    @DatabaseField(columnDefinition = "age")    private int age;    public Student() {    }    public Student(String name, String sex, String address, int age) {        this.name = name;        this.sex = sex;        this.address = address;        this.age = age;    }    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 getSex() {        return sex;    }    public void setSex(String sex) {        this.sex = sex;    }    public String getAddress() {        return address;    }    public void setAddress(String address) {        this.address = address;    }    public int getAge() {        return age;    }    public void setAge(int age) {        this.age = age;    }}

首先在Student类上添加@DatabaseTable(tableName = "tb_student")，标明这是数据库中的一张表，标明为tb_student，

然后分别在属性上添加@DatabaseField(columnName = "name") ，columnName的值为该字段在数据中的列名

@DatabaseField(generatedId = true) ，generatedId 表示id为主键且自动生成

3、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，看代码：

package db;import android.content.Context;import android.database.sqlite.SQLiteDatabase;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;import java.sql.SQLException;/** * Created by wls on 2016/10/4. */public class DatabaseHelper extends OrmLiteSqliteOpenHelper{    private static final String TABLE_NAME = "sqlite-test.db";    private static DatabaseHelper daHelper;    /**     * studentDao 每张表对于一个     */    private Dao<Student,Integer> studentDao;    public DatabaseHelper(Context context) {        super(context, TABLE_NAME, null, 1);    }    @Override    public void onCreate(SQLiteDatabase sqLiteDatabase,                         ConnectionSource connectionSource) {        try {            TableUtils.createTable(connectionSource,Student.class);        } catch (SQLException e) {            e.printStackTrace();        }    }    @Override    public void onUpgrade(SQLiteDatabase sqLiteDatabase,                          ConnectionSource connectionSource, int i, int i1) {        try {            TableUtils.dropTable(connectionSource,Student.class,true);            onCreate(sqLiteDatabase,connectionSource);        } catch (SQLException e) {            e.printStackTrace();        }    }    /**     * 单里获取该Helper     * @param context     * @return     */    public static synchronized DatabaseHelper getDaHelper(Context context){        if(daHelper == null){            synchronized (DatabaseHelper.class){                if(daHelper == null){                    daHelper = new DatabaseHelper(context);                }            }        }        return daHelper;    }    /**     * 获得studentDao     * @return     * @throws SQLException     */    public Dao<Student, Integer> getStudentDao() throws SQLException{        if(studentDao == null){            studentDao = getDao(Student.class);        }        return studentDao;    }    /**     * 释放资源     */    @Override    public void close() {        super.close();        studentDao = null;    }}

这里我们需要继承OrmLiteSqliteOpenHelper，其实就是间接继承了SQLiteOpenHelper

然后需要实现两个方法：

1、onCreate(SQLiteDatabase database,ConnectionSource connectionSource)

创建表，我们直接使用ormlite提供的TableUtils.createTable(connectionSource, User.class);进行创建~

2、onUpgrade(SQLiteDatabase database, ConnectionSource connectionSource, int oldVersion, int newVersion)

更新表，使用ormlite提供的TableUtils.dropTable(connectionSource, User.class, true);进行删除操作~

删除完成后，别忘了，创建操作：onCreate(database, connectionSource);

然后使用单例公布出一个创建实例的方法，getHelper用于获取我们的help实例；

最后我们可能会有很多表嘛，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：

4、把StudentDao类单独提取出来：

package db;import android.content.Context;import java.sql.SQLException;/** * Created by wls on 2016/10/4. */public class StudentDao {    private Context context;    public StudentDao(Context context) {        this.context = context;    }    public void add(Student student){        try {            DatabaseHelper.getDaHelper(context).getStudentDao().create(student);        } catch (SQLException e)        {        }    }//......}

5、具体的操作配置（增删改查）

package db;import android.content.Context;import android.test.AndroidTestCase;import android.util.Log;import java.sql.SQLException;import java.util.List;/** * Created by wls on 2016/10/4. */public class StudentHelper extends AndroidTestCase{    private static final String TAG = "print";    private DatabaseHelper datahelper;    public StudentHelper(Context context){        datahelper = DatabaseHelper.getDaHelper(context);    }    /**     * 插入数据     * @param name     * @param sex     * @param address     * @param age     */    public void insertData(String name,String sex,String address,int age){        Student student = new Student(name,sex,address,age);        try {            datahelper.getStudentDao().create(student);            Log.d(TAG, "insertData: "+"插入成功");        } catch (SQLException e) {            e.printStackTrace();        }    }    /**     * 查询数据（全部）     */    public void queryAllData(){        try {            List<Student> list = datahelper.getStudentDao().queryForAll();            for(int i = 0;i<list.size();i++){                Log.d(TAG, "queryAllData: "+list.get(i).getName()+"----"+list.get(i).getSex()                +"----"+list.get(i).getAddress()+"----"+list.get(i).getAge());            }        } catch (SQLException e) {            e.printStackTrace();        }    }    /**     * 查询数据（根据数据）     * @param address     */    public void queryData(String address){        try {            List<Student> list = datahelper.getStudentDao().queryBuilder().where().eq("address",address).query();            for(int i = 0;i<list.size();i++){                Log.d(TAG, "queryData: "+list.get(i).getName()+"----"+list.get(i).getSex()                        +"----"+list.get(i).getAddress()+"----"+list.get(i).getAge());            }        } catch (SQLException e) {            e.printStackTrace();        }    }    /**     * 更新数据     * @param name     * @param sex     * @param address     * @param age     */    public void updata(String name,String sex,String address,int age){        try {            List<Student> list = datahelper.getStudentDao().queryBuilder().where().eq("sex",sex).query();            if(list.size()>0){                Student student = new Student(name,sex,address,age);                student.setId(list.get(0).getId());                datahelper.getStudentDao().update(student);            }        } catch (SQLException e) {            e.printStackTrace();        }    }    /**     * 删除（根据条件）     * @param name     */    public void delectData(String name){        try {            List<Student> list = datahelper.getStudentDao().queryBuilder().where().eq("name",name).query();            int id = list.get(0).getId();            datahelper.getStudentDao().deleteById(id);        } catch (SQLException e) {            e.printStackTrace();        }    }    /**     * 删除全部     */    public void delectAllData(){        try {            datahelper.getStudentDao().deleteBuilder().delete();            List<Student> list = datahelper.getStudentDao().queryForAll();            Log.d(TAG, "delectAllData: "+list.size());        } catch (SQLException e) {            e.printStackTrace();        }    }}

6、至此，基本的配置结束，下面为测试代码：

XML文件：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical"    tools:context="com.example.wls.ormliteandroid.MainActivity">   <Button       android:id="@+id/insertData"       android:layout_width="wrap_content"       android:layout_height="wrap_content"       android:textSize="14sp"       android:text="插入数据"       android:onClick="btnClick"/>    <Button        android:id="@+id/queryData"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:textSize="14sp"        android:text="查询数据"        android:onClick="btnClick"/>    <Button        android:id="@+id/upData"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:textSize="14sp"        android:text="修改数据"        android:onClick="btnClick"/>    <Button        android:id="@+id/delectData"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:textSize="14sp"        android:text="删除数据"        android:onClick="btnClick"/></LinearLayout>

MainActivtiy：

public class MainActivity extends AppCompatActivity {    private Student student;    private StudentHelper studentHelper;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        student = new Student();        studentHelper = new StudentHelper(this);    }    public void btnClick(View view){        switch (view.getId()){            case R.id.insertData:                studentHelper.insertData("进藤光","男","东京",12);                studentHelper.insertData("藤原佐为","男","神户",1000);                studentHelper.insertData("小明","女","东京",10);                studentHelper.insertData("塔矢亮","男","东京",12);                studentHelper.insertData("小红","女","北京",15);                break;            case R.id.queryData:                studentHelper.queryAllData();                studentHelper.queryData("东京");                break;            case R.id.upData:                studentHelper.updata("进藤光","男","东京",20);                break;            case R.id.delectData:              //  studentHelper.delectData("小明");                studentHelper.delectAllData();                break;        }    }}

根据打印的LOG可观察不同的操作所展示的效果。对于该框架的进一步了解，请看：http://blog.csdn.net/lmj623565791/article/details/39122981