Android studio，使用greenDao第三方数据库框架操作数据库

因项目有需求，需建一个数据库来存储数据，数据库选型就选了当前比较流行，性能也比较好的greenDao，目前使用的版本是3.2.0，简单易用，下面具体说下使用的步骤：

1.在build.gradle文件导入配置文件，导入包

//greenDao----start//
apply plugin: 'org.greenrobot.greendao'
buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath 'org.greenrobot:greendao-gradle-plugin:3.2.0'
    }
}
greendao {
    schemaVersion 1    //<--数据库的版本，用于升级时候进行更改
    daoPackage 'com.example.pc.teste6.dao'     //存放自动生成代码的包
    targetGenDir 'src/main/java'                  //...
}
//greenDao----end//

//greeDao所需要的支持
compile 'org.greenrobot:greendao:3.2.0'
compile 'org.greenrobot:greendao-generator:3.2.0'

2.greenDao非常智能化，接着只需写你的数据库实体类，就能生成对应的表了，例如

public class UserObject {

    //这个注解就表明下面那个id是个主键，必须用Long，否则会报错，autoincrement=true自增
    @Id(autoincrement = true)
    Long id;
    @NotNull
    String name;
    //不为空
    @NotNull
    Integer age;


    }

接着按Ctrl+F9,就会生成get和set方法，并且在你的dao包下生成数据库文件和dao类

@Entity
public class UserObject {

    //这个注解就表明下面那个id是个主键，必须用Long，否则会报错，autoincrement=true自增
    @Id(autoincrement = true)
    Long id;
    @NotNull
    String name;
    //不为空
    @NotNull
    Integer age;
    @Generated(hash = 824938356)
    public UserObject(Long id, @NotNull String name, @NotNull Integer age) {
        this.id = id;
        this.name = name;
        this.age = age;
    }
    @Generated(hash = 1300257024)
    public UserObject() {
    }
    public Long getId() {
        return this.id;
    }
    public void setId(Long id) {
        this.id = id;
    }
    public String getName() {
        return this.name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Integer getAge() {
        return this.age;
    }
    public void setAge(Integer age) {
        this.age = age;
    }


    

3.写一个DBDaoUtil类，操作数据库

public class DBDaoUtil {

    private static DaoSession daoSession;
    private static DaoSession getDaoSession(Context context) {
        if (daoSession==null) {
            DaoMaster.OpenHelper openHelper = new DaoMaster.OpenHelper(context, "student"){
                @Override
                public void onUpgrade(Database db, int oldVersion, int newVersion) {
                    switch (oldVersion) {
                        case 1:
                            db.beginTransaction();
                            db.execSQL("...");
                            db.setTransactionSuccessful();
                            db.endTransaction();
                            break;
                    }
                }
            };
            SQLiteDatabase db = openHelper.getWritableDatabase();
            DaoMaster daoMaster = new DaoMaster(db);
            daoSession = daoMaster.newSession();
        }
        return daoSession;
    }

    public static UserObjectDao getUserDao(Context context) {
        return getDaoSession(context).getUserObjectDao();
    }
}

4.通过mainActivity,操作数据库

activity_main.xml文件

xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.pc.teste6.MainActivity">

    <LinearLayout
        android:id="@+id/dataLL"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">
        <Button
            android:id="@+id/add"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@+id/network"
            android:text="增"/>
        <Button
            android:id="@+id/delete"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@+id/add"
            android:text="删"/>
        <Button
            android:id="@+id/update"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@+id/delete"
            android:text="改"/>
        <Button
            android:id="@+id/select"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@+id/update"
            android:text="查"/>

    LinearLayout>

    <ListView
        android:id="@+id/dataLV"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/dataLL">

    ListView>
RelativeLayout>

Mainactivity

import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import com.example.pc.teste6.bean.UserObject;
import com.example.pc.teste6.dao.UserObjectDao;
import com.example.pc.teste6.receiver.BatteryReceiver;
import com.example.pc.teste6.util.DBDaoUtil;
import com.example.pc.teste6.util.NetUtil;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity implements View.OnClickListener{


    private Context context;
    private Button addBtn,deleteBtn,updateBtn,selectBtn;//增删改查
    private ListView dataLV;
    private DataAdapter adapter;
    private UserObjectDao userDao;
    private int i=1;




    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        context=this;

        initView();
        initData();

    }


    /**
     * 初始化控件
     */
    private void initView(){
        addBtn= (Button) findViewById(R.id.add);
        deleteBtn= (Button) findViewById(R.id.delete);
        updateBtn= (Button) findViewById(R.id.update);
        selectBtn= (Button) findViewById(R.id.select);
        dataLV= (ListView) findViewById(R.id.dataLV);

       
        addBtn.setOnClickListener(this);
        deleteBtn.setOnClickListener(this);
        updateBtn.setOnClickListener(this);
        selectBtn.setOnClickListener(this);

    }

    /**
     * 初始化数据
     */
    private void initData(){

        userDao = DBDaoUtil.getUserDao(context);//初始化dao

        adapter=new DataAdapter(context);
        dataLV.setAdapter(adapter);

       
    }


    @Override
    public void onClick(View view) {
        switch (view.getId()){
           
            case R.id.add:
                UserObject ub1=new UserObject();
                ub1.setName("小小英"+i);
                ub1.setAge(100);
                userDao.insert(ub1);
                List list1=userDao.loadAll();
                adapter.addData(list1);
                i++;
                break;
            case R.id.delete:
                userDao.deleteByKey(Long.parseLong(i+""));
                List list2=userDao.loadAll();
                adapter.addData(list2);
                break;
            case R.id.update:
                UserObject ub3=new UserObject();
                ub3.setId(Long.parseLong(i+""));
                userDao.update(ub3);
                List list3=userDao.loadAll();
                adapter.addData(list3);
                break;
            case R.id.select://查询数据
                List list4=userDao.loadAll();
                adapter.addData(list4);
                Toast.makeText(context,""+list4.size(),Toast.LENGTH_SHORT).show();
                break;
            default:
                break;

        }
    }


    class DataAdapter extends BaseAdapter{

        private Context context;
        private List mList;


        public DataAdapter(Context context) {
            this.context = context;
        }

        public void addData(List mList){
            this.mList=mList;
            notifyDataSetChanged();
        }

        @Override
        public int getCount() {
            return (mList!=null)?mList.size():1;
        }

        @Override
        public Object getItem(int i) {
            return mList.get(i);
        }

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

        @Override
        public View getView(int i, View view, ViewGroup viewGroup) {

            view = LayoutInflater.from(context).inflate(R.layout.lv_item,null);
            if(mList!=null&&mList.size()!=0){
                TextView idTV= (TextView) view.findViewById(R.id.idTV);
                idTV.setText(mList.get(i).getId()+"");
                TextView nameTV= (TextView) view.findViewById(R.id.nameTv);
                nameTV.setText(mList.get(i).getName());
                TextView ageTV= (TextView) view.findViewById(R.id.ageTv);
                ageTV.setText(mList.get(i).getAge()+"");
            }
            return view;
        }
    }

}

这样就可以操作数据库了

我的心愿是世界和平。。。