cant fill dataset

Question

I run the string in Oracle SQL developer and i get data howerver when I try to fill the dataset I get 0 rows and 0 columns.

 

code is as follows:

 

string from_date = "01/28/2020";

string to_date = "01/29/2020";

 

string queryString = "SELECT d.materialcode AS MATCODE, m.itemdesc AS ITEMS, sum(d.quantity) AS QUANTITY FROM tbldispensed d " +

"right outer join tblmasterinventory m on m.materialcode = d.materialcode " +

"WHERE TO_DATE(d.datedispensed, 'yy/mm/dd') BETWEEN TO_DATE('"+ from_date + "', 'mm/dd/yyyy') " +

"AND TO_DATE('" + to_date + "', 'mm/dd/yyyy') " +

"GROUP BY d.materialcode, m.itemdesc";

 

conn.Open();

OdbcDataAdapter da = new OdbcDataAdapter(queryString, conn);

DataSet ds = new DataSet();

da.Fill(ds);

 

MessageBox.Show(ds.Tables[0].Rows.Count.ToString());

 

I get 0 rows....can you help please