数据库————App

第一步

App 类里面

public class App extends Application {
    static App app;
    private DaoSession daoSession;

    @Override
    public void onCreate() {
        super.onCreate();
        app=this;
        getMyDaoSessage();
    }

    public static App getApp(){
        return app;
    }

    public void getMyDaoSessage() {

        DaoMaster.DevOpenHelper yiKu = new DaoMaster.DevOpenHelper(this, "sssssss");
        SQLiteDatabase db = yiKu.getWritableDatabase();
        DaoMaster daoMaster = new DaoMaster(db);
        daoSession = daoMaster.newSession();

    }

    public DaoSession getDaoSession(){
        return daoSession;
    }
}

第二步

数据库的添加

1.在Manactivty中直接跳转就ok

Intent intent = new Intent(MainActivity.this, AddActivity.class);
startActivity(intent);

2. 在AddActivity中

@Override
public void onClick(View v) {
    switch (v.getId()) {
        case R.id.bt_comit:
            BeanADao beanADao = App.getApp().getDaoSession().getBeanADao();
            //2.new 一个数据库对象
            BeanA beanA = new BeanA();
            //3.
            beanA.setText(ed_text.getText().toString());
            beanA.setName(ed_name.getText().toString());
            beanADao.insert(beanA);
            finish();
            break;
    }

数据库的查询

List<BeanA> beanAs = App.getApp().getDaoSession().getBeanADao().loadAll();
adapter = new RecyAdapter(MainActivity.this,beanAs);
LinearLayoutManager manager = new LinearLayoutManager(MainActivity.this);
manager.setOrientation(LinearLayoutManager.VERTICAL);
recy.setLayoutManager(manager);
recy.setAdapter(adapter);

数据库的删除

bt_delete.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        List<BeanA> beanAs = App.getApp().getDaoSession().getBeanADao().loadAll();
        Long id = beanAs.get(position).getId();
        App.getApp().getDaoSession().getBeanADao().deleteByKey(id);
        query();
      
    }
});

数据库的修改

1.第一步在MainActivty中

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update.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        List<BeanA> beanAs1 = App.getApp().getDaoSession().getBeanADao().loadAll();
        Intent intent = new Intent(MainActivity.this, UpdataActivity.class);
        intent.putExtra("Id",beanAs1.get(position).getId());
       intent.putExtra("text",beanAs1.get(position).getText());
       intent.putExtra("name",beanAs1.get(position).getName());
        startActivity(intent);

    }
});

2.第二步在修改Activity中写一个方法先接受值

Intent intent = getIntent();
id = intent.getLongExtra("Id", -1);
text = intent.getStringExtra("text");
String name = intent.getStringExtra("name");
ed2_text.setText(text);
ed2_name.setText(name);

3.在提交按钮中

switch (v.getId()) {
    case R.id.bt2_comit:
        
        BeanA beanA = new BeanA();
        beanA.setImage_("http://p2.so.qhimgs1.com/t016c021483304f34be.jpg");
        beanA.setText(ed2_text.getText().toString());
        beanA.setName(ed2_name.getText().toString());
        beanA.setId(id);
        App.getApp().getDaoSession().getBeanADao().update(beanA);
        finish();
        break;
}

数据库————App

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