Does anyone meet this error?

Update unable to find TableMapping['Table'] or DataTable 'Table'

I use northwind database,


The cod is bellow:

Thanks ahead!

string uid = (string)(Session["uid"]);

MyConnection = new SqlConnection();

MyConnection.ConnectionString = "Data Source=.\\SQLEXPRESS;AttachDbFilename=|DataDirectory|\\NORTHWND.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True";

SqlDataAdapter custDA = new SqlDataAdapter("SELECT CustomerID,CompanyName FROM Customers",MyConnection);

custDA.UpdateCommand=new SqlCommand("UPDATE Customers SET CompanyName=@CompanyName WHERE CustomerID=@CustomerID",MyConnection);

custDA.UpdateCommand.Parameters.Add("@CompanyName",SqlDbType.NVarChar,15,"CompanyName");

SqlParameter workParm=custDA.UpdateCommand.Parameters.Add("@CustomerID",SqlDbType.NChar,5,"CustomerID");

workParm.SourceColumn="CustomerID";

workParm.SourceVersion=DataRowVersion.Original;

workParm.Value = uid;

DataSet custDS = new DataSet();

custDA.Fill(custDS, "Customers");

DataRow cRow = custDS.Tables["Customers"].Rows[0];

cRow["CompanyName"]="new Category";

custDA.Update(custDS)