The DataSet Designer utilizes primitive .NET Data Types (e.g. System.Int32 and System.Decimal) by default. It maps Teradata Decimal Data Type to System.Decimal. System.Decimal has a maximum Precision of 29 and maximum Scale of 28. This default mapping cannot handle Teradata Decimal with precision greater than 29 or Scale greater than 28.

TdDecimal is a provider specific type with maximum precision and scale of 38. DbDataAdapter.ReturnProviderSpecificTypes property controls the Fill and FillSchema methods. This property by default is set to false per ADO.NET specification. It can be set to true to create DataColumns of type TdDecimal.

How to Generate a Typed DataSet with TdDecimal Type DataColumns

• Create and Configure a TdDataAdapter.
  1. Drag TdDataAdapter component from the Toolbox to a Form design surface.
  2. Right-Click on the instance of TdDataAdapter and select Properties.
  3. Set ReturnProviderSpecificTypes property to True.
  4. Left-Click "Configure Data Adapter..." task and the bottom of the Properties window.
     1. Select a data connection or create a New Connection; Click Next.
     2. Select "Use SQL Statements".
     3. Type a SELECT statement or use "Query Builder..." to create a SELECT statement; Click Next.
     4. Click Finish.
• Generate a Typed DataSet
  1. Right-Click on the instance of TdDataAdapter and select Properties.
  2. Left-Click "Generate DataSet...".
     1. Choose an Existing DataSet or a new DataSet.
     2. Select the instance of TdDataAdapter in "Choose which table(s) to add to the dataset".
     3. Select "Add this dataset to the designer."
     4. Click OK.

How to Fill a Typed DataSet

The Typed DataSet generated in steps above will not have a TableAdapter. However you can use TdDataAdapter.Fill method on an instance of the Typed DataSet.

private void Form1_Load(object sender, EventArgs e)
{
    tdDataAdapter1.Fill(this.largeDecimalDataSet1);
}

How to Save Updates to a Typed DataSet

The Typed DataSet generated in steps above will not have a TableAdapter.  However you can use TdDataAdapter.Update method on an instance of the Typed DataSet.

private void largeDecimalBindingNavigatorSaveItem_Click(object sender, EventArgs e)
{
    tdDataAdapter1.Update(this.largeDecimalDataSet1);
}