Can't add more than one row to DataSet

Question

Here's the code:

DataSet1.CashRow CashRow = MainDataSet.Cash.NewCashRow();
CashRow.SetIdNull();
CashRow.Date = CashItem.Date;
CashRow.Description = CashItem.Description;
CashRow.Amount = CashItem.Amount;
MainDataSet.Cash.Rows.Add(CashRow);

It works just fine for the first time. However, if put in a cycle and simply doubled, no more rows are added. I have to close application and start it again.

Update: I have a DataGridView which is connected to the DataSet. Could this cause any problems? This issue is really weird, been trying to fix this for a week now. Maybe there are another ways to add rows?

Update 2: found the cause: "System.Data.ConstraintException: Column 'Id' is constrained to be unique. Value '' is already present.".

Answer 1

try this:

DataSet1.CashRow CashRow = MainDataSet.Cash.NewCashRow();
CashRow.Date = CashItem.Date;
CashRow.Description = CashItem.Description;
CashRow.Amount = CashItem.Amount;

MainDataSet.Cash.AddCashRow(CashRow);

CashTableAdapter.Update(MainDataSet);

And if it still update only one row put this block as function, like this:

private void CreateCashRow (DateTime date, string description, int amount)
{
   DataSet1.CashRow CashRow = MainDataSet.Cash.NewCashRow();
   CashRow.Date = date;
   CashRow.Description = description;
   CashRow.Amount = amount;

   MainDataSet.Cash.AddCashRow(CashRow);

   CashTableAdapter.Update(MainDataSet);
}

And call the function as many time you need.

You must make sure you have PrimaryKey on the table

• I also suggest to you not to use so similar names for vars and types like you did with the CashRow.