Dao层+sql语句

1.Dao层

public class Dao {

private Mysql mysql;
private SQLiteDatabase database;

public Dao(Context context){
    mysql = new Mysql(context);
    database = mysql.getWritableDatabase();
}
public void add(String _id,String title,String content){
    ContentValues values = new ContentValues();
    values.put("_id",_id);
    values.put("title",title);
    values.put("content",content);
    database.insert("user",null,values);
}

public List<Bean.DataBean> cha(){
    List<Bean.DataBean> list = new ArrayList<>();
    Cursor query = database.query("user", null, null, null, null, null, null);
    while (query.moveToNext()){
        String _id = query.getString(query.getColumnIndex("_id"));
        String title = query.getString(query.getColumnIndex("title"));
        String content = query.getString(query.getColumnIndex("content"));
        Bean.DataBean bean = new Bean.DataBean();
        bean.setNews_id(_id);
        bean.setNews_title(title);
        bean.setNews_summary(content);
        list.add(bean);
    }
    return list;
}

public void del(){
    database.delete("user",null,null);
}
}

2.SQL表

public class Mysql extends SQLiteOpenHelper {
    public Mysql(Context context) {
        super(context, "User.db", null, 1);
    }

@Override
public void onCreate(SQLiteDatabase db) {
    db.execSQL("create table user (id integer primary key autoincrement," +
            "_id next," +
            "title next," +
            "content next)");
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

    }
}