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How to: Extend the Functionality of a TableAdapter

You can extend the functionality of a TableAdapter by adding code to the TableAdapter's partial class file.

The code that defines a TableAdapter is regenerated when any changes are made to the TableAdapter (in the Dataset Designer) or when changes are made during the running of any wizard that modifies the configuration of a TableAdapter. To prevent your code from being deleted during the regeneration of a TableAdapter, add code to the TableAdapter's partial class file.

(Partial classes allow code for a specific class to be divided among multiple physical files. For more information, see Partial (Visual Basic) or partial (Type) (C# Reference).)

While TableAdapters are designed with the Dataset Designer, the TableAdapter classes generated are not generated as nested classes of the DataSet. TableAdapters are located in a namespace based on the name of the TableAdapter's associated dataset. For example, if your application contains a dataset named HRDataSet, the TableAdapters would be located in the HRDataSetTableAdapters namespace. (The naming convention follows this pattern: DatasetName + TableAdapters).

The following example assumes a TableAdapter named CustomersTableAdapter in a project with a NorthwindDataSet.

To create a partial class for a TableAdapter

  1. Add a new class to your project by choosing Add Class from the Project menu.

  2. Name the class CustomersTableAdapterExtended.

  3. Click Add.

  4. Replace the code with the proper namespace and partial class name for your project. For example:

    namespace NorthwindDataSetTableAdapters
        public partial class CustomersTableAdapter
            // Add user code here. For example: 
            public override string ToString()
                return "Overridden in the partial class.";