GreenDao数据库框架的配置与增删改查

时间：2022-03-08 12:08:41

并非原创，原创地址http://blog.csdn.net/njweiyukun/article/details/51893092

配置----------------------------------

　　项目的gradle里的配置

apply plugin: 'org.greenrobot.greendao'

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath 'org.greenrobot:greendao-gradle-plugin:3.0.0'
    }
}
 在gradle的根模块中加入上述代码后，sync project的时候，gradle会自动去maven仓库下载一个gradle的插件，当然了，这个插件就是为greenDAO服务的，用来生成数据库相关的代码。
greendao {
    schemaVersion 1
    daoPackage 'com.greendao.demo.gen'
    targetGenDir 'src/main/java'
}

schemaVersion---->指定数据库schema版本号，迁移等操作会用到

daoPackage-------->通过gradle插件生成的数据库相关文件的包名，默认为你的entity所在的包名

targetGenDir-------->这就是我们上面说到的自定义生成数据库文件的目录了，可以将生成的文件放到我们的java目录中，而不是build中，这样就不用额外的设置资源目录了

导包

  1. compile 'org.greenrobot:greendao:3.0.1'
  2. compile 'org.greenrobot:greendao-generator:3.0.0'
在根目录创建entity包名  定义实体数据库类
@Entity：将我们的java普通类变为一个能够被greenDAO识别的数据库类型的实体类

@Id：通过这个注解标记的字段必须是Long类型的，这个字段在数据库中表示它就是主键，并且它默认就是自增的

@Transient：表明这个字段不会被写入数据库，只是作为一个普通的java类字段，用来临时存储数据的，不会被持久化

重新编译后会生成一些代码以及gen目录

@Entity
public class User {
    @Id
    private Long id;
    private String name;
    @Transient
    private int tempUsageCount; // not persisted
    public String getName() {
        return this.name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Long getId() {
        return this.id;
    }
    public void setId(Long id) {
        this.id = id;
    }
    @Generated(hash = 873297011)
    public User(Long id, String name) {
        this.id = id;
        this.name = name;
    }
    @Generated(hash = 586692638)
    public User() {
    }
}

初始化数据库
public class GreenDaoManager {
    private static GreenDaoManager mGreenDaoManager;
    private DaoMaster mMaster;
    private DaoSession mDaosession;

    public GreenDaoManager() {
        DaoMaster.DevOpenHelper devOpenHelper=new DaoMaster.DevOpenHelper(MyLication.getContext(),"user-db",null);
        mMaster=new DaoMaster(devOpenHelper.getWritableDatabase());
        mDaosession=mMaster.newSession();
    }
    public static GreenDaoManager getInstance(){
        if(mGreenDaoManager==null){
            mGreenDaoManager=new GreenDaoManager();
        }
        return mGreenDaoManager;
    }
    public DaoMaster getMaster(){
        return mMaster;
    }
    public DaoSession getDaosession(){
        return mDaosession;
    }
    public DaoSession getNewDasession(){
        mDaosession=mMaster.newSession();
        return mDaosession;
    }
}
出数据库中用的APPlication
public class MyLication extends Application {
    private static Context mContext;

    @Override
    public void onCreate() {
        super.onCreate();
        mContext=getApplicationContext();
        GreenDaoManager.getInstance();
    }
    public static Context getContext(){
        return mContext;
    }
}
自动生成的3个类

activity代码  包涵增删改查

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    private EditText mNameET;
    private Button mAddBtn;
    private ListView mUserLV;
    private UserAdapter mUserAdapter;
    private List<User> mUserList = new ArrayList<>();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
        initData();
    }

    private void initData() {
        mUserList= GreenDaoManager.getInstance().getDaosession().getUserDao().queryBuilder().build().list();
        mUserAdapter = new UserAdapter(this, mUserList);
        mUserLV.setAdapter(mUserAdapter);
    }

    private void initView() {
        mNameET = (EditText) findViewById(R.id.et_name);
        mAddBtn = (Button) findViewById(R.id.btn_add);
        mUserLV = (ListView) findViewById(R.id.lv_user);
        findViewById(R.id.btn_delete).setOnClickListener(this);
        findViewById(R.id.btn_update).setOnClickListener(this);

        mAddBtn.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        int viewId = v.getId();
        switch (viewId){
            case R.id.btn_add:
                insertUser(null, mNameET.getText().toString());
                break;
            case R.id.btn_delete:
                deleteUser("li");
                break;
            case R.id.btn_update:
                updateUser("y","li");
                break;
        }
    }
    private void updateUser(String name,String newName){
        UserDao userDao= GreenDaoManager.getInstance().getDaosession().getUserDao();
        User findUser=userDao.queryBuilder()
                .where(UserDao.Properties.Name.eq(name)).build().unique();
        if(findUser!=null){
            findUser.setName(newName);
            GreenDaoManager.getInstance().getDaosession().getUserDao().update(findUser);
            ToaskUtil.showToast(this,"修改成功");
            updateAdapter(userDao.queryBuilder().list());
            mUserAdapter.notifyDataSetChanged();
        }else{
            ToaskUtil.showToast(this,"没有找到该用户信息");
        }
    }
    private void deleteUser(String name){
        UserDao userDao=GreenDaoManager.getInstance().getDaosession().getUserDao();
       User findUser=userDao .queryBuilder().where(UserDao.Properties.Name.eq(name)).build().unique();
        if(findUser!=null){
            userDao.deleteByKey(findUser.getId());
            ToaskUtil.showToast(this,"删除成功");
            updateAdapter(userDao.queryBuilder().list());
        }else{
            ToaskUtil.showToast(this,"没有找到该用户");
        }
    }
    private void insertUser(Long id,String name){
       UserDao userDao= GreenDaoManager.getInstance().getDaosession().getUserDao();
        User user=new User(id,name);
        userDao.insert(user);
        mNameET.setText("");
        updateAdapter(userDao.queryBuilder().list());

    }
    private void updateAdapter(List<User> list){
        mUserList.clear();
        mUserList.addAll(list);
        mUserAdapter.notifyDataSetChanged();
    }
}
activity的布局文件
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
   >

    <EditText
        android:id="@+id/et_name"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <Button
        android:id="@+id/btn_add"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="add one" />
    <Button
        android:id="@+id/btn_delete"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="delete one" />
    <Button
        android:id="@+id/btn_update"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="update one" />

    <ListView
        android:id="@+id/lv_user"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>
</LinearLayout>

ListView的Adapter
package com.greendao.demo.Adapter;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import com.greendao.demo.R;
import com.greendao.demo.entity.User;

import java.util.List;

/**
 * Created by Administrator on 2016/10/10.
 */
public class UserAdapter extends BaseAdapter {
    private List<User> mUserList;
    private Context mContext;

    public UserAdapter(Context mContext, List<User> mUserList) {
        this.mUserList = mUserList;
        this.mContext = mContext;
    }

    @Override
    public int getCount() {
        return mUserList == null ? 0 : mUserList.size();
    }

    @Override
    public Object getItem(int position) {
        return position;
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder viewHolder = null;
        if (convertView == null) {
            convertView = LayoutInflater.from(mContext).inflate(R.layout.item_user, null);
            viewHolder = new ViewHolder();
            viewHolder.tv_id = (TextView) convertView.findViewById(R.id.tv_id);
            viewHolder.tv_name = (TextView) convertView.findViewById(R.id.tv_name);
            convertView.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) convertView.getTag();
        }

        User user = mUserList.get(position);
        viewHolder.tv_id.setText(String.valueOf(user.getId()));
        viewHolder.tv_name.setText(user.getName());

        return convertView;
    }

    class ViewHolder {
        TextView tv_id;
        TextView tv_name;
    }
}
Adapter的布局
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
    <LinearLayout
        android:layout_marginTop="5dp"
        android:layout_width="match_parent"
        android:layout_height="30dp"
        android:orientation="horizontal">
        <TextView
            android:id="@+id/tv_id"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="1"
            android:layout_marginLeft="15dp"
            android:textSize="25dp"/>
        <TextView
            android:id="@+id/tv_name"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:text="zhangsan"
            android:textSize="25dp"/>
    </LinearLayout>
    <View
        android:layout_marginTop="3dp"
        android:layout_width="match_parent"
        android:layout_height="2dp"
        android:background="@android:color/holo_blue_bright"/>
</LinearLayout>
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