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[ Team LiB ] Recipe 3.14 Using the Shape Language to Retrieve Hierarchical Data Problem You want to use the Shape language with ADO.NET to retrieve hierarchical data from a SQL Server. | Team LiB Recipe 3.14 Using the Shape Language to Retrieve Hierarchical Data Problem You want to use the Shape language with ADO.NET to retrieve hierarchical data from a SQL Server. Solution Execute the SHAPE command as shown in the following example using the OLE DB provider. The sample code defines a SHAPE query to retrieve the TOP 5 Orders from Northwind and the Order Details for each of the Orders. A DataReader based on the query is created. The code iterates over the rows in the DataReader displaying the data for each Order row. If the value for the column can be cast to the IDataReader interface it is a DataReader containing the Order Details for the Order row. The value for the column is cast to a DataReader and the collection of records is iterated over and displayed. The C code is shown in Example 3-14. Example 3-14. File ShapeForm.cs Namespaces variables and constants using System using System.Configuration using System.Text using System.Data using System.Data.OleDb . . . StringBuilder result new StringBuilder SHAPE SQL to retrieve TOP five Orders and associated Order Detail records. String shapeText SHAPE select TOP 5 from Orders AS Orders APPEND select from Order Details AS Order Details RELATE OrderlD TO OrderlD Create the connection. OleDbConnection conn new OleDbConnection ConfigurationSettings.AppSettings OleDb_Shape_ConnectString Create a command and fill a DataReader with the SHAPE result set. OleDbCommand cmd new OleDbCommand shapeText conn conn.Open OleDbDataReader orderDR cmd.ExecuteReader Iterate over the collection of rows in the DataReader. while orderDR.Read result.Append ORDER Environment.NewLine Iterate over the collection of Order columns in the DataReader. for int colOrder 0 colOrder orderDR.FieldCount colOrder if orderDR colOrder is IDataReader The column is an IDataReader interface. result.Append Environment.NewLine result.Append orderDR.GetName colOrder .ToUpper Environment.NewLine Create a DataReader for the Order Detail from the .