DataSet inherit problem

[sbdSolna]

I have a DataSet called DataHolder, that holdes several tables. The DataHolder class is a UserControl, that also holds the connection to the database.
When the Dataholder starts it fills in different SqlDataAdapters with commands used for selects, deletes and updates of different tables.
Here is the problem, one of the tables has no inserts and therefore I use this code.

if (this.dataHolder.HasChanges(DataRowState.Modified)) {
    DataSet tempDS = this.dataHolder.GetChanges (DataRowState.Modified);
  if  tempDS.Tables.ContainsDataHolder.TableNameProdDataPre)){ 			this.dataHolder.SqlPreviewDataAdapter.Update (tempDS, DataHolder.TableNameProdDataPre);
						this.dataHolder.AcceptChanges();
 }
}

That code does not work the statement this.dataHolder.GetChanges(DataRowState.Modified) goes through the Constructor of DataHolder.

If I do like this the code works ok

if (this.dataHolder.HasChanges(DataRowState.Modified)) {
    DataSet tempDS = this.dataHolder.GetChanges();
    if (tempDS.Tables.Contains(DataHolder.TableNameProdDataPre)) {
					this.dataHolder.SqlPreviewDataAdapter.Update(tempDS, DataHolder.TableNameProdDataPre);
						this.dataHolder.AcceptChanges();
  }
}

Do anyone know why?

Thanks in advance.

 

[Kalisto]

Post the declaration of your GetChanges Function. It looks to me like there isnt one that takes an additional parameter.

When you say it doesnt work, what happens, any error messages? What happens if you step through it in the debugger?

K

 

[sbdSolna]

Here is an example from Msdn on HasChanges and GetChanges

   if(ds.HasChanges(DataRowState.Modified | DataRowState.Added)& ds.HasErrors){
      // Use GetChanges to extract subset.
      xSet = ds.GetChanges(DataRowState.Modified|DataRowState.Added);
      PrintValues(xSet, "Subset values");
      // Insert code to reconcile errors. In this case, we'll reject changes.
      foreach(DataTable xTable in xSet.Tables){
         if (xTable.HasErrors){
            foreach(DataRow xRow in xTable.Rows){
               //Console.WriteLine(xRow["Item"]);
                  if((int)xRow["Item",DataRowVersion.Current ]> 100){
                  xRow.RejectChanges();
                  xRow.ClearErrors();
               }
            }
         }
      }

From the example:

xSet = ds.GetChanges(DataRowState.Modified|DataRowState.Added);


Yes GetChanges can take several parameters but I'm only using one.

When I step through the code, with F11. I come down to the constructor of DataHolder that is inherit from the DataSet. But the code works with GetChanges with no parameters

 

[Kalisto]

So what happens when your code runs? Nothing gets put into the dataset?

K

 

[sbdSolna]

You can't see the problem, if you not debug the code with.
But DataHolder also has a other function. That is to switch between production and test tables.
I you only work in production is no problem, but if you work with test, the constructor of DataHolder going to switch to production tables during GetChanges(), and that is a really big problem.

 

[bobisto]

in the first sample code I notice that you have sintax error with parenthesis:

if (this.dataHolder.HasChanges(DataRowState.Modified))
{
	DataSet tempDS = this.dataHolder.GetChanges (DataRowState.Modified);
	if  [COLOR=red]([/color red]tempDS.Tables.ContainsDataHolder.TableNameProdDataPre) //[COLOR=red])[/color red]
	{            
		this.dataHolder.SqlPreviewDataAdapter.Update (tempDS, DataHolder.TableNameProdDataPre);
		this.dataHolder.AcceptChanges();
	}
}

but try with this added code lines:

			if (this.dataHolder.HasChanges(DataRowState.Modified))
			{
				DataSet tempDS = new DataSet();
				tempDS = (DataSet)this.dataHolder.GetChanges(DataRowState.Modified);
				if (tempDS.Tables.ContainsDataHolder.TableNameProdDataPre)
				{            
					this.dataHolder.SqlPreviewDataAdapter.Update(tempDS, DataHolder.TableNameProdDataPre);
					this.dataHolder.AcceptChanges();
				}
			}
[code]