SQL增加删除

    private String sql = "create table student(_id integer primary key autoincrement," + "name text not null)";

这里是创建数据库的语句
    public MyDBHelper(Context context) {
        super(context, "studentInfo", null, 1);

    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL(sql);
    }


    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("drop table if exists student");
        onCreate(db);
    }
}

接下来我们就要获取数据

    private int _id;
    private String name;
    public Name(){
    }
    public Name(String name){
        this.name=name;
    }
    public int get_id() {
        return _id;
    }
    public void set_id(int _id) {
        this._id = _id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }

}

接下来我们就要加入增加删除SQL语句的方法
这里可不能弄错

private Context context;
    private MyDBHelper helper;
    private SQLiteDatabase db;

    public NameDAO(Context context){
        helper=new MyDBHelper(context);
    }
    public void insert(Name name){
        
        db=helper.getWritableDatabase();
        
        ContentValues values=new ContentValues();
        values.put("name",name.getName());
        
        db.insert("student",null,values);

       String sql ="insert into student(name,classmate,age)"+"values(?,?,?)";
       db.execSQL(sql,new Object[]{
               student.getName(),
                student.getClassmate(),
               student.getAge()});
    }

    public Cursor selectAll() {
        db =helper.getReadableDatabase();
        Cursor cursor= db.query("student",null,null,null,null,null,null);
        return cursor;
    }
    public void delete(int id){
        db = helper.getWritableDatabase();
        db.delete("student","_id=?",new String[]{String.valueOf(id)});
       String sql="delete from student where _id=?";
        db.execSQL(sql,new Object[]{id});
    }
}
然后接下来

public MyCursorAdapter(Context context, Cursor c) {
    super(context, c, 0);
}

@Override
public View newView(Context context, Cursor cursor, ViewGroup viewGroup) {
    return LayoutInflater.from(context).inflate(R.layout.item,viewGroup,false);
}

@Override
public void bindView(View view, Context context, Cursor cursor) {
    TextView name= (TextView) view.findViewById(R.id.tvname);
    name.setText(cursor.getString(cursor.getColumnIndex("name")));

}
最后一步

onCreate方法

btnadd= (Button) findViewById(R.id.add);
btndelete= (Button) findViewById(R.id.delete);
    btnadd.setOnClickListener(this);
    btndelete.setOnClickListener(this);
    lvshow= (ListView) findViewById(R.id.list_show);
    nameDAO=new NameDAO(this);
    cursor=nameDAO.selectAll(); //调用NameDAO中的selectALl（）方法，即查询数据
    if(cursor!=null){
        adapter=new MyCursorAdapter(this,cursor);
       lvshow.setAdapter(adapter);//根据游标将数据传递到listview中显示
    }

后面的东西不懂，上面的截图参考丁同学的。

说真的，做这个东西很多都弄的不是很明白

感觉东西和别人差不多，但是最后总是不能运行

最后放上别人帮我弄的成果图