RUN SQL STATEMENT IN DATASET by match case

public static DataSet Getdataset1(string filename1)
        {
            string Connectionstring = string.Format("Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0};Extended Properties=Text;",
          Path.GetDirectoryName(filename1));
          
            string cmdstring = string.Format(@"select * FROM {0} order by IN_no desc,FIRST_DATE asc,END_DATE asc", Path.GetFileName(filename1));
            string cmdstring1 = string.Format(@"select * FROM {0} order by IN no desc,FIRST DATE asc,END DATE asc",
 Path.GetFileName(filename1));
string cmdstring2 = string.Format(@"select * FROM {0} order by Pd_no desc,FIRST_DATE asc,END DATE asc", Path.GetFileName(filename1));
            DataSet dataset = new DataSet();
            using (OleDbConnection olconn = new OleDbConnection(Connectionstring))
            {
                olconn.Open();
                OleDbDataAdapter adapter = new OleDbDataAdapter();
                adapter.SelectCommand = new OleDbCommand(cmdstring, olconn);
                adapter.SelectCommand= new OleDbCommand(cmdstring1, olconn);
                adapter.SelectCommand= new OleDbCommand(cmdstring2, olconn);
                dataset.Clear();
                adapter.Fill(dataset, "Test");
                olconn.Close();
            }
            return dataset;
        }
        public void Process_Click(object sender, EventArgs e)
        {
            
           
            try
            {
                DataSet dataset = Form1.Getdataset1(Locations.Text);
                Datagidveiw1.DataSource = dataset.Tables[0].DefaultView;
             
              
            }
            catch (System.Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }
    }
}