Is this proper way to handle typed DataSets (why the TableAdapter does not update the database)?

Question

I need some help. Here is the problem: I have two typed datasets: one is related to the Access DB with an empty table (localDB) and another one is related to the Access database DB2 with a table containing 1925 records (localDB2). I want to copy data from DB2 table to DB empty table and it does not work. DB and DB2 are copied in Debug folder at runtime. The below is the code:

        try
        {
            // Loading DB (with 0 records in the table CompanyAccount)
            LocalDBDataSetTableAdapters.CompanyAccountTableAdapter adapter = new LocalDBDataSetTableAdapters.CompanyAccountTableAdapter();
            LocalDBDataSet localDB = new LocalDBDataSet();
            adapter.Fill(localDB.CompanyAccount);

            // Loading DB2 with 1925 records in table CompanyAccount
            LocalDBCopyDataSetTableAdapters.CompanyAccountTableAdapter adapter2 = new LocalDBCopyDataSetTableAdapters.CompanyAccountTableAdapter();
            LocalDBCopyDataSet localDB2 = new LocalDBCopyDataSet();
            adapter2.Fill(localDB2.CompanyAccount);

            // try to merge empty table with popoulated table.
            // this seems to work, as per watched variables in the debugger
            localDB.Merge(localDB2.CompanyAccount);

            // is this necessary?
            localDB.CompanyAccount.AcceptChanges();

            // try to save DB does not work, no errors, only rec = 0
            int rec = adapter.Update(localDB.CompanyAccount);

        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }
        finally
        {
            Console.WriteLine("Press a key to exit.");
            Console.ReadKey();
        }

After merging, the table CompanyAccount in localDB gets 1925 records. After adapter.Update method was called on the same table, the variable rec=0 and database does not receive any record.

Can someone tell me why this does not work or what I am doing wrong? Thanks a lot

Answer 1

Take a look at the RowState property of the Rows in your CompanyAccount table ... RowState should be "Added" after the Merge ... but AcceptChanges resets the RowStates to "Unchanged". That's the Reason why Update doesn't do anything ... If you don't call AcceptChanges the update should trigger Insert statements.

If you want all rows of localDB.CompanyAccount to have RowState == Added you could also use this the Load() function instead of Merge:

localDB.CompanyAccount.Load(new DataTableReader(localDB2.CompanyAccount), LoadOption.Upsert);