dao 包中的Dao层方法

public class Dao {
//写数据库记得在清单文件中写读写权限
private final OpenHelper helper;
private final SQLiteDatabase database;

public Dao(Context context){     helper = new OpenHelper(context);     database = helper.getWritableDatabase(); } public long add(Bean.DataBean bean){     ContentValues values = new ContentValues();     values.put("news_id",bean.getNews_id());     values.put("news_title",bean.getNews_title());     values.put("news_summary",bean.getNews_summary());     values.put("pic_url",bean.getPic_url());     long insert = database.insert("user", null, values);     return insert; } //查询 public List<Bean.DataBean> queryAll(){     Cursor cursor = database.query("user", null, null, null, null, null, null);     List<Bean.DataBean> list=new ArrayList<>();     while (cursor.moveToNext()){         String news_id = cursor.getString(cursor.getColumnIndex("news_id"));         String news_title = cursor.getString(cursor.getColumnIndex("news_title"));         String news_summary = cursor.getString(cursor.getColumnIndex("news_summary"));         String pic_url = cursor.getString(cursor.getColumnIndex("pic_url"));          Bean.DataBean bean=new Bean.DataBean(news_id, news_summary, news_title, pic_url);         list.add(bean);      }     return list; } 

}

文章来源: https://blog.csdn.net/qq_42631085/article/details/86436506