The first row of my SQLite Database is not getting fetched and displayed in my RecyclerView

Question

This is my dbmanager class:

public class dbmanager extends SQLiteOpenHelper {

    String sgpa_table="create table Sgpa (sname text, semester text, sgpa  int,percent int, schemes int, primary key(sname,semester,schemes))";


    public dbmanager(@Nullable Context context) {
        super(context, "Student", null, 1);
    }

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

    }

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

    }

    public Cursor fetch_data1() {
        SQLiteDatabase db = this.getWritableDatabase();
        String query = "Select*FROM Sgpa" ;
        Cursor cursor = db.rawQuery(query,null);
        if (cursor != null) {
           cursor.moveToFirst();
        }
        return cursor;
    }
}

This is my Adapter class:

public class adapter_sgpa extends RecyclerView.Adapter<adapter_sgpa.Viewholder> {

    ArrayList<POJO> sgpaArrayList;

    public adapter_sgpa(ArrayList<POJO> sgpaArrayList) {
        this.sgpaArrayList = sgpaArrayList;
    }

    @NonNull
    @Override
    public adapter_sgpa.Viewholder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {

        View listitem = LayoutInflater.from(parent.getContext()).inflate(R.layout.recycler_sgpa, parent, false);
        return new Viewholder(listitem);
    }

    @Override
    public void onBindViewHolder(@NonNull adapter_sgpa.Viewholder holder, int position) {


        POJO sgpa= sgpaArrayList.get(position);
        holder.sname.setText(sgpa.getSname());
        holder.semester.setText(sgpa.getSemester());
        holder.sgpa.setText(Integer.toString(sgpa.getSgpa()));
        holder.percent.setText(Integer.toString(sgpa.getPercent()));
        holder.schemes.setText(Integer.toString(sgpa.getSchemes()));
    }

    @Override
    public int getItemCount() {
        return sgpaArrayList.size();
    }

    public class Viewholder extends RecyclerView.ViewHolder {

        TextView sname, semester, sgpa, percent, schemes;
        //ImageButton btndelete1;

        public Viewholder(@NonNull View itemView) {
            super(itemView);

            sname = (TextView) itemView.findViewById(R.id.textView2);
            semester = (TextView) itemView.findViewById(R.id.semester);
            sgpa = (TextView) itemView.findViewById(R.id.textV);
            percent = (TextView) itemView.findViewById(R.id.textVw);
            schemes = (TextView) itemView.findViewById(R.id.scheme1);
          //  btndelete1 = (ImageButton) itemView.findViewById(R.id.btndelete1);
        }
    }
}

This is sgpa_frag which is like my main class:

public class sgpa_frag extends Fragment {
    //View view;
    RecyclerView recyclerview;
    adapter_sgpa ac;
    TextView else2;

    ArrayList<POJO> sgpaArrayList;

    public sgpa_frag() {
        // Required empty public constructor
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

    }

    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_sgpa_frag, container, false);
        recyclerview= (RecyclerView) view.findViewById(R.id.rc1);
        else2=(TextView)view.findViewById(R.id.else2);
        sgpaArrayList= new ArrayList<>();
        ac= new adapter_sgpa(sgpaArrayList);
        recyclerview.setLayoutManager(new LinearLayoutManager(getContext(),RecyclerView.VERTICAL,true));
        recyclerview.setAdapter(ac);

        Fetchdata1();

        return view;
    }

    private void Fetchdata1()
    {
        dbmanager db= new dbmanager(getContext());

        Cursor cursor= db.fetch_data1();

        if (cursor!= null){

            cursor.moveToFirst();

            while (cursor.moveToNext()){
                //ModelDetail cd= new ModelDetail(cursor.getString(1),cursor.getString(2),cursor.getString(3),cursor.getString(4));

                POJO pj= new POJO();
                pj.setSname(cursor.getString(0));
                pj.setSemester(cursor.getString(1));
                pj.setSgpa(cursor.getInt(2));
                pj.setPercent(cursor.getInt(3));
                pj.setSchemes(cursor.getInt(4));
                sgpaArrayList.add(pj);
            }

            ac= new adapter_sgpa(sgpaArrayList);
            recyclerview.setAdapter(ac);
        }
        else{
            else2.setVisibility(View.VISIBLE);
        }
    }
}

The first row of my SQLite Database is not getting fetched and displayed in my RecyclerView. The other rows are getting displayed but only the first one is not getting displayed. Can someone point me out where I am going wrong?

Answer 1

From this part of your code in Fetchdata1():

if (cursor!= null){
    cursor.moveToFirst();
    while (cursor.moveToNext()){
..................................

remove cursor.moveToFirst();
because cursor.moveToNext() will advance the cursor's index to the 2nd row and the 1st row will not be added to the list.
Also inside fetch_data1() inside dbmanager remove this:

if (cursor != null) {
   cursor.moveToFirst();
}