Question

如何解决该错误如何获取数组列表在Cursor对象中返回结果查询集。有一些常用的方法可以用于游标

public class DBAdapter {
        Context c;
        CluecatalogOpenHelper helper;
        SQLiteDatabase db;
        int flag=0;

        public DBAdapter(Context ctx) {
            super();
            this.c = ctx;
            helper=new CluecatalogOpenHelper(ctx);
        }
        public void openDB(){

            db=helper.getWritableDatabase();
        }
        public void closeDB(){
            db.close();
        }

        public void addRow(String name, byte[] data1) {

                openDB();
                ContentValues values = new ContentValues();
                values.put("name", name); 
                values.put("object",data1);
                db.insert("topsearch", null, values);
                closeDB();        
        }


        public void deleteRow(String name)
        {
        try {
db.execSQL("delete from topsearch where name = (?)",new String[]{""+name});
      } catch (SQLException e) {
        e.printStackTrace();
                                }
        }

        public Cursor showData(){
        try{
         Cursor c = db.query("topsearch", new String[]{"name","object"}, null, null,null, null,null);
            return c;
            }catch(Exception e) {
            e.printStackTrace();
            return null;
            }}}

如何解决该错误

Answer 1

我不确定你究竟在问什么，但是如果你问如何从Cursor对象和List中取出结果你会这样做：

List list = new ArrayList();
Cursor c = db.query("topsearch", new String[]{"name","object"}, null, null,null, null,null);

while(c.moveToNext())
{
    //populate your return object from the cursor here
    //i'm just making this part up
    Obj obj = new Obj();

    obj.setName(c.getString(0));  //0 being the column index

    list.add(obj);
}

return list;

将内容添加到数据库中

1 个答案: