Modifying Data with Stored Procedures (ADO.NET)

Stored procedures can accept data as input parameters and can return data as output parameters, result sets, or return values. The sample below illustrates how ADO.NET sends and receives input parameters, output parameters, and return values. The example inserts a new record into a table where the primary key column is an identity column in a SQL Server database.

Example

The sample uses the following stored procedure to insert a new category into the Northwind Categories table. The stored procedure takes the value in the CategoryName column as an input parameter and uses the SCOPE_IDENTITY() function to retrieve the new value of the identity field, CategoryID, and return it in an output parameter. The RETURN statement uses the @@ROWCOUNT function to return the number of rows inserted.

CREATE PROCEDURE dbo.InsertCategory
  @CategoryName nvarchar(15),
  @Identity int OUT
AS
INSERT INTO Categories (CategoryName) VALUES(@CategoryName)
SET @Identity = SCOPE_IDENTITY()
RETURN @@ROWCOUNT

The following code example uses the InsertCategory stored procedure shown above as the source for the InsertCommand of the SqlDataAdapter. The @Identity output parameter will be reflected in the DataSet after the record has been inserted into the database when the Update method of the SqlDataAdapter is called. The code also retrieves the return value.

Private Sub ReturnIdentity(ByVal connectionString As String)
    Using connection As SqlConnection = New SqlConnection( _
       connectionString)

        ' Create a SqlDataAdapter based on a SELECT query.
        Dim adapter As SqlDataAdapter = New SqlDataAdapter( _
           "SELECT CategoryID, CategoryName FROM dbo.Categories", _
           connection)

        ' Create a SqlCommand to execute the stored procedure. 
        adapter.InsertCommand = New SqlCommand("dbo.InsertCategory", _
           connection)
        adapter.InsertCommand.CommandType = CommandType.StoredProcedure

        ' Create a parameter for the ReturnValue.
        Dim parameter As SqlParameter = _
           adapter.InsertCommand.Parameters.Add( _
          "@RowCount", SqlDbType.Int)
        parameter.Direction = ParameterDirection.ReturnValue

        ' Create an input parameter for the CategoryName.
        ' You do not need to specify direction for input parameters.
        adapter.InsertCommand.Parameters.Add( _
          "@CategoryName", SqlDbType.NChar, 15, "CategoryName")

        ' Create an output parameter for the new identity value.
        parameter = adapter.InsertCommand.Parameters.Add( _
          "@Identity", SqlDbType.Int, 0, "CategoryID")
        parameter.Direction = ParameterDirection.Output

        ' Create a DataTable and fill it.
        Dim categories As DataTable = New DataTable
        adapter.Fill(categories)

        ' Add a new row.
        Dim newRow As DataRow = categories.NewRow()
        newRow("CategoryName") = "New Category"
        categories.Rows.Add(newRow)

        ' Update the database.
        adapter.Update(categories)

        ' Retrieve the ReturnValue.
        Dim rowCount As Int32 = _
           CInt(adapter.InsertCommand.Parameters("@RowCount").Value)

        Console.WriteLine("ReturnValue: {0}", rowCount.ToString())
        Console.WriteLine("All Rows:")
        Dim row As DataRow
        For Each row In categories.Rows
            Console.WriteLine("  {0}: {1}", row(0), row(1))
        Next
    End Using
End Sub

private static void ReturnIdentity(string connectionString)
{
    using (SqlConnection connection =
               new SqlConnection(connectionString))
    {
        // Create a SqlDataAdapter based on a SELECT query.
        SqlDataAdapter adapter = new SqlDataAdapter(
          "SELECT CategoryID, CategoryName FROM dbo.Categories",
          connection);

        // Create a SqlCommand to execute the stored procedure.
        adapter.InsertCommand = new SqlCommand("InsertCategory", connection);
        adapter.InsertCommand.CommandType = CommandType.StoredProcedure;

        // Create a parameter for the ReturnValue.
        SqlParameter parameter = adapter.InsertCommand.Parameters.Add(
          "@RowCount", SqlDbType.Int);
        parameter.Direction = ParameterDirection.ReturnValue;

        // Create an input parameter for the CategoryName.
        // You do not need to specify direction for input parameters.
        adapter.InsertCommand.Parameters.Add(
          "@CategoryName", SqlDbType.NChar, 15, "CategoryName");

        // Create an output parameter for the new identity value.
        parameter = adapter.InsertCommand.Parameters.Add(
          "@Identity", SqlDbType.Int, 0, "CategoryID");
        parameter.Direction = ParameterDirection.Output;

        // Create a DataTable and fill it.
        DataTable categories = new DataTable();
        adapter.Fill(categories);

        // Add a new row.
        DataRow categoryRow = categories.NewRow();
        categoryRow["CategoryName"] = "New Beverages";
        categories.Rows.Add(categoryRow);

        // Update the database.
        adapter.Update(categories);

        // Retrieve the ReturnValue.
        Int32 rowCount =
            (Int32)adapter.InsertCommand.Parameters["@RowCount"].Value;

        Console.WriteLine("ReturnValue: {0}", rowCount.ToString());
        Console.WriteLine("All Rows:");
        foreach (DataRow row in categories.Rows)
        {
            {
                Console.WriteLine("  {0}: {1}", row[0], row[1]);
            }
        }
    }
}

See Also

Concepts

Executing a Command (ADO.NET)

Other Resources

Retrieving and Modifying Data in ADO.NET

DataAdapters and DataReaders (ADO.NET)

ADO.NET Managed Providers and DataSet Developer Center