How to compare the database value and string value in vb.net using csharp

Con = new SqlConnection("Server=(local)\\SQLEXPRESS;Initial Catalog=MyDatabase;Integrated Security=SSPI");
SqlCommand cmd = new SqlCommand();
cmd.CommandText = ("Select * from table where name='"+ txtSearch.Text +"');
cmd.Connection = con;
try {
    con.Open();
   sqlDataReader dr = cmd.Executereader();

 if(dr.hasRows)
 {
  while(dr.Read())
 {
   string AFF = dr["Id"].ToString() + " " + dr.["Address"].ToString();
 }
}

}
finally {
    con.Close();
}

//First get database data and store it into one temporary table like datatable.

DataTable dt=//database data;

//assuming you have string data like below. 

string data="hello";

now you want to compare string result with datatable result then use below sample code.

if(data==dt.Rows[rowindex]["col"].ToString())
{
   //matches
}
else
{
  //mis match
}