Binding a Windows DataGrid to Master-Detail Data

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[ Team LiB ] Recipe 7.12 Binding a Windows DataGrid to Master-Detail Data Problem You need to bind both a parent table and child table within a DataSet to a DataGrid so that the child data is displayed when the parent is expanded, and update the database with edits made to data in both tables.

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Nội dung Text: Binding a Windows DataGrid to Master-Detail Data

[ Team LiB ] Recipe 7.12 Binding a Windows DataGrid to Master-Detail Data Problem You need to bind both a parent table and child table within a DataSet to a DataGrid so that the child data is displayed when the parent is expanded, and update the database with edits made to data in both tables. Solution Use the approach demonstrated in the sample code. The sample uses eight stored procedures, which are shown in Example 7-20 through Example 7-27: GetOrders Used to retrieve a single record from the Orders table if the optional @OrderId parameter is specified or all Orders records if it is not DeleteOrders Used to delete the record specified by the @OrderId parameter from the Orders table InsertOrders Used to insert a record into the Orders table and return the OrderID identity value for the new record UpdateOrders Used to update all field values for the record in the Orders table specified by the @OrderId input parameter GetOrderDetails Used to retrieve a single record from the Order Details table if the optional @OrderId and @ProductID parameters are specified, or all Order Details records if it is not DeleteOrderDetails
Used to delete the record specified by the @OrderId and @ProductID parameters from the Order Details table InsertOrderDetails Used to insert a record into the Order Details table UpdateOrderDetails Used to update all field values for the record in the Order Details table specified by the @OrderId and @ProductID input parameters Example 7-20. Stored procedure: GetOrders CREATE PROCEDURE GetOrders @OrderID int=null AS SET NOCOUNT ON if @OrderID is not null begin select OrderID, CustomerID, EmployeeID, OrderDate, RequiredDate, ShippedDate, ShipVia, Freight, ShipName, ShipAddress, ShipCity, ShipRegion, ShipPostalCode, ShipCountry from Orders where OrderID=@OrderID return 0
end select OrderID, CustomerID, EmployeeID, OrderDate, RequiredDate, ShippedDate, ShipVia, Freight, ShipName, ShipAddress, ShipCity, ShipRegion, ShipPostalCode, ShipCountry from Orders return 0 Example 7-21. Stored procedure: DeleteOrders CREATE PROCEDURE DeleteOrders @OrderID int AS SET NOCOUNT ON delete from Orders where OrderID=@OrderID return 0 Example 7-22. Stored procedure: InsertOrders CREATE PROCEDURE InsertOrders @OrderID int output, @CustomerID nchar(5), @EmployeeID int,
@OrderDate datetime, @RequiredDate datetime, @ShippedDate datetime, @ShipVia int, @Freight money, @ShipName nvarchar(40), @ShipAddress nvarchar(60), @ShipCity nvarchar(15), @ShipRegion nvarchar(15), @ShipPostalCode nvarchar(10), @ShipCountry nvarchar(15) AS SET NOCOUNT ON insert Orders( CustomerID, EmployeeID, OrderDate, RequiredDate, ShippedDate, ShipVia, Freight, ShipName, ShipAddress, ShipCity, ShipRegion, ShipPostalCode, ShipCountry) values ( @CustomerID, @EmployeeID, @OrderDate, @RequiredDate, @ShippedDate, @ShipVia, @Freight, @ShipName, @ShipAddress, @ShipCity, @ShipRegion, @ShipPostalCode, @ShipCountry)
if @@rowcount=0 return 1 set @OrderID=Scope_Identity( ) select @OrderId OrderId return 0 Example 7-23. Stored procedure: UpdateOrders CREATE PROCEDURE UpdateOrders @OrderID int, @CustomerID nchar(5), @EmployeeID int, @OrderDate datetime, @RequiredDate datetime, @ShippedDate datetime, @ShipVia int, @Freight money, @ShipName nvarchar(40), @ShipAddress nvarchar(60), @ShipCity nvarchar(15), @ShipRegion nvarchar(15), @ShipPostalCode nvarchar(10), @ShipCountry nvarchar(15) AS SET NOCOUNT ON update Orders set CustomerID=@CustomerID, EmployeeID=@EmployeeID, OrderDate=@OrderDate, RequiredDate=@RequiredDate, ShippedDate=@ShippedDate, ShipVia=@ShipVia, Freight=@Freight, ShipName=@ShipName, ShipAddress=@ShipAddress, ShipCity=@ShipCity, ShipRegion=@ShipRegion,
ShipPostalCode=@ShipPostalCode, ShipCountry=@ShipCountry where OrderID=@OrderID if @@rowcount=0 return 1 return 0 Example 7-24. Stored procedure: GetOrderDetails CREATE PROCEDURE GetOrderDetails @OrderID int=null, @ProductID int=null AS SET NOCOUNT ON if @OrderID is not null and @ProductID is not null begin select OrderID, ProductID, UnitPrice, Quantity, Discount from [Order Details] where OrderID=@OrderID and ProductID=@ProductID return 0 end select OrderID, ProductID, UnitPrice, Quantity, Discount from [Order Details]
return 0 Example 7-25. Stored procedure: DeleteOrderDetails CREATE PROCEDURE DeleteOrderDetails @OrderID int, @ProductID int AS SET NOCOUNT ON delete from [Order Details] where OrderID=@OrderID and ProductID=@ProductID return 0 Example 7-26. Stored procedure: InsertOrderDetails CREATE PROCEDURE InsertOrderDetails @OrderID int, @ProductID int, @UnitPrice money, @Quantity smallint, @Discount real AS SET NOCOUNT ON insert [Order Details]( OrderID, ProductID, UnitPrice, Quantity, Discount) values ( @OrderID, @ProductID, @UnitPrice, @Quantity, @Discount)
if @@rowcount=0 return 1 return 0 Example 7-27. Stored procedure: UpdateOrderDetails CREATE PROCEDURE UpdateOrderDetails @OrderID int, @ProductID int, @UnitPrice money, @Quantity smallint, @Discount real AS SET NOCOUNT ON update [Order Details] set UnitPrice=@UnitPrice, Quantity=@Quantity, Discount=@Discount where OrderID=@OrderID and ProductID=@ProductID if @@rowcount=0 return 1 return 0 The sample code contains two event handlers: Form.Load Sets up the sample by creating a DataSet containing the Orders and Order Details DataTable objects. A DataRelation object is created relating the tables. DataAdapter objects are created for each DataTable; the select, delete, insert, and update Command objects are specified for each using the custom logic in the eight stored procedures used by this solution. The DataAdapter objects are used to fill both tables in the DataSet. Finally, the default view of the Orders table is bound to
the data grid on the form. Update Button.Click Uses the DataAdapter for the Orders and Order Details DataTable objects to update offline changes back to the database. The C# code is shown in Example 7-28. Example 7-28. File: HierarchicalDataGridForm.cs // Namespaces, variables, and constants using System; using System.Configuration; using System.Data; using System.Data.SqlClient; private DataSet ds; // Private SqlDataAdapter daParent, daChild private SqlDataAdapter daOrder, daOrderDetail; // Table name constants private const String ORDERS_TABLE = "Orders"; private const String ORDERDETAILS_TABLE = "OrderDetails"; // Relation name constants private const String ORDERS_ORDERDETAILS_RELATION = "Orders_OrderDetails_Relation"; // Field name constants for Orders table public const String ORDERID_FIELD = "OrderID"; public const String CUSTOMERID_FIELD = "CustomerID"; public const String EMPLOYEEID_FIELD = "EmployeeID"; public const String ORDERDATE_FIELD = "OrderDate"; public const String REQUIREDDATE_FIELD = "RequiredDate"; public const String SHIPPEDDDATE_FIELD = "ShippedDate"; public const String SHIPVIA_FIELD = "ShipVia"; public const String FREIGHT_FIELD = "Freight"; public const String SHIPNAME_FIELD = "ShipName"; public const String SHIPADDRESS_FIELD = "ShipAddress"; public const String SHIPCITY_FIELD = "ShipCity"; public const String SHIPREGION_FIELD = "ShipRegion"; public const String SHIPPOSTALCODE_FIELD = "ShipPostalCode";
public const String SHIPCOUNTRY_FIELD = "ShipCountry"; // Stored procedure name constants public const String DELETEORDERS_SP = "DeleteOrders"; public const String GETORDERS_SP = "GetOrders"; public const String INSERTORDERS_SP = "InsertOrders"; public const String UPDATEORDERS_SP = "UpdateOrders"; // Stored procedure parameter name constants for Orders table public const String ORDERID_PARM = "@OrderID"; public const String CUSTOMERID_PARM = "@CustomerID"; public const String EMPLOYEEID_PARM = "@EmployeeID"; public const String ORDERDATE_PARM = "@OrderDate"; public const String REQUIREDDATE_PARM = "@RequiredDate"; public const String SHIPPEDDDATE_PARM = "@ShippedDate"; public const String SHIPVIA_PARM = "@ShipVia"; public const String FREIGHT_PARM = "@Freight"; public const String SHIPNAME_PARM = "@ShipName"; public const String SHIPADDRESS_PARM = "@ShipAddress"; public const String SHIPCITY_PARM = "@ShipCity"; public const String SHIPREGION_PARM = "@ShipRegion"; public const String SHIPPOSTALCODE_PARM = "@ShipPostalCode"; public const String SHIPCOUNTRY_PARM = "@ShipCountry"; // Field name constants for OrderDetails table public const String ORDERID_FIELD = "OrderID"; public const String PRODUCTID_FIELD = "ProductID"; public const String UNITPRICE_FIELD = "UnitPrice"; public const String QUANTITY_FIELD = "Quantity"; public const String DISCOUNT_FIELD = "Discount"; // Stored procedure name constants public const String DELETEORDERDETAILS_SP = "DeleteOrderDetails"; public const String GETORDERDETAILS_SP = "GetOrderDetails"; public const String INSERTORDERDETAILS_SP = "InsertOrderDetails"; public const String UPDATEORDERDETAILS_SP = "UpdateOrderDetails"; // Stored procedure parameter name constants for OrderDetails table public const String ORDERID_PARM = "@OrderID"; public const String PRODUCTID_PARM = "@ProductID"; public const String UNITPRICE_PARM = "@UnitPrice"; public const String QUANTITY_PARM = "@Quantity"; public const String DISCOUNT_PARM = "@Discount";
// . . . private void HierarchicalDataGridForm_Load(object sender, System.EventArgs e) { ds = new DataSet( ); // Fill the Order table and add it to the DataSet. daOrder = new SqlDataAdapter(GETORDERS_SP, ConfigurationSettings.AppSettings["Sql_ConnectString"]); daOrder.SelectCommand.CommandType = CommandType.StoredProcedure; DataTable dtOrder = new DataTable(ORDERS_TABLE); daOrder.FillSchema(dtOrder, SchemaType.Source); daOrder.Fill(dtOrder); ds.Tables.Add(dtOrder); // Fill the OrderDetails table with schema and add it to the DataSet. daOrderDetail = new SqlDataAdapter(GETORDERDETAILS_SP, ConfigurationSettings.AppSettings["Sql_ConnectString"]); daOrderDetail.SelectCommand.CommandType = CommandType.StoredProcedure; DataTable dtOrderDetail = new DataTable(ORDERDETAILS_TABLE); daOrderDetail.FillSchema(dtOrderDetail, SchemaType.Source); daOrderDetail.Fill(dtOrderDetail); ds.Tables.Add(dtOrderDetail); // Create a relation between the tables. ds.Relations.Add(ORDERS_ORDERDETAILS_RELATION, ds.Tables[ORDERS_TABLE].Columns[ORDERID_FIELD], ds.Tables[ORDERDETAILS_TABLE].Columns[ORDERID_FIELD], true); // Build the orders delete command. SqlCommand deleteCommand = new SqlCommand(DELETEORDERS_SP, daOrder.SelectCommand.Connection); deleteCommand.CommandType = CommandType.StoredProcedure; SqlParameterCollection sqlParams = deleteCommand.Parameters; sqlParams.Add(ORDERID_PARM, SqlDbType.Int, 0, ORDERID_FIELD); daOrder.DeleteCommand = deleteCommand; // Build the orders insert command. SqlCommand insertCommand = new SqlCommand(INSERTORDERS_SP, daOrder.SelectCommand.Connection);
insertCommand.CommandType = CommandType.StoredProcedure; sqlParams = insertCommand.Parameters; sqlParams.Add(ORDERID_PARM, SqlDbType.Int, 0, ORDERID_FIELD).Direction = ParameterDirection.Output; sqlParams.Add(CUSTOMERID_PARM, SqlDbType.NChar, 5, CUSTOMERID_FIELD); sqlParams.Add(EMPLOYEEID_PARM, SqlDbType.Int, 0, EMPLOYEEID_FIELD); sqlParams.Add(ORDERDATE_PARM, SqlDbType.DateTime, 0, ORDERDATE_FIELD); sqlParams.Add(REQUIREDDATE_PARM, SqlDbType.DateTime, 0, REQUIREDDATE_FIELD); sqlParams.Add(SHIPPEDDDATE_PARM, SqlDbType.DateTime, 0, SHIPPEDDDATE_FIELD); sqlParams.Add(SHIPVIA_PARM, SqlDbType.Int, 0, SHIPVIA_FIELD); sqlParams.Add(FREIGHT_PARM, SqlDbType.Money, 0, FREIGHT_FIELD); sqlParams.Add(SHIPNAME_PARM, SqlDbType.NVarChar, 40, SHIPNAME_FIELD); sqlParams.Add(SHIPADDRESS_PARM, SqlDbType.NVarChar, 60, SHIPADDRESS_FIELD); sqlParams.Add(SHIPCITY_PARM, SqlDbType.NVarChar, 15, SHIPCITY_FIELD); sqlParams.Add(SHIPREGION_PARM, SqlDbType.NVarChar, 15, SHIPREGION_FIELD); sqlParams.Add(SHIPPOSTALCODE_PARM, SqlDbType.NVarChar, 10, SHIPPOSTALCODE_FIELD); sqlParams.Add(SHIPCOUNTRY_PARM, SqlDbType.NVarChar, 15, SHIPCOUNTRY_FIELD); daOrder.InsertCommand = insertCommand; // Build the orders update command. SqlCommand updateCommand = new SqlCommand(UPDATEORDERS_SP, daOrder.SelectCommand.Connection); updateCommand.CommandType = CommandType.StoredProcedure; sqlParams = updateCommand.Parameters; sqlParams.Add(ORDERID_PARM, SqlDbType.Int, 0, ORDERID_FIELD); sqlParams.Add(CUSTOMERID_PARM, SqlDbType.NChar, 5, CUSTOMERID_FIELD); sqlParams.Add(EMPLOYEEID_PARM, SqlDbType.Int, 0, EMPLOYEEID_FIELD); sqlParams.Add(ORDERDATE_PARM, SqlDbType.DateTime, 0, ORDERDATE_FIELD); sqlParams.Add(REQUIREDDATE_PARM, SqlDbType.DateTime, 0, REQUIREDDATE_FIELD); sqlParams.Add(SHIPPEDDDATE_PARM, SqlDbType.DateTime, 0, SHIPPEDDDATE_FIELD);
sqlParams.Add(SHIPVIA_PARM, SqlDbType.Int, 0, SHIPVIA_FIELD); sqlParams.Add(FREIGHT_PARM, SqlDbType.Money, 0, FREIGHT_FIELD); sqlParams.Add(SHIPNAME_PARM, SqlDbType.NVarChar, 40, SHIPNAME_FIELD); sqlParams.Add(SHIPADDRESS_PARM, SqlDbType.NVarChar, 60, SHIPADDRESS_FIELD); sqlParams.Add(SHIPCITY_PARM, SqlDbType.NVarChar, 15, SHIPCITY_FIELD); sqlParams.Add(SHIPREGION_PARM, SqlDbType.NVarChar, 15, SHIPREGION_FIELD); sqlParams.Add(SHIPPOSTALCODE_PARM, SqlDbType.NVarChar, 10, SHIPPOSTALCODE_FIELD); sqlParams.Add(SHIPCOUNTRY_PARM, SqlDbType.NVarChar, 15, SHIPCOUNTRY_FIELD); daOrder.UpdateCommand = updateCommand; // Build the order details delete command. deleteCommand = new SqlCommand(DELETEORDERDETAILS_SP, daOrderDetail.SelectCommand.Connection); deleteCommand.CommandType = CommandType.StoredProcedure; sqlParams = deleteCommand.Parameters; sqlParams.Add(ORDERID_PARM, SqlDbType.Int, 0, ORDERID_FIELD); sqlParams.Add(PRODUCTID_PARM, SqlDbType.Int, 0, PRODUCTID_FIELD); daOrderDetail.DeleteCommand = deleteCommand; // Build the order details insert command. insertCommand = new SqlCommand(INSERTORDERDETAILS_SP, daOrderDetail.SelectCommand.Connection); insertCommand.CommandType = CommandType.StoredProcedure; sqlParams = insertCommand.Parameters; sqlParams.Add(ORDERID_PARM, SqlDbType.Int, 0, ORDERID_FIELD); sqlParams.Add(PRODUCTID_PARM, SqlDbType.Int, 0, PRODUCTID_FIELD); sqlParams.Add(UNITPRICE_PARM, SqlDbType.Money, 0, UNITPRICE_FIELD); sqlParams.Add(QUANTITY_PARM, SqlDbType.SmallInt, 0, QUANTITY_FIELD); sqlParams.Add(DISCOUNT_PARM, SqlDbType.Real, 0, DISCOUNT_FIELD); daOrderDetail.InsertCommand = insertCommand; // Build the order details update command. updateCommand = new SqlCommand(UPDATEORDERDETAILS_SP, daOrderDetail.SelectCommand.Connection); updateCommand.CommandType = CommandType.StoredProcedure; sqlParams = updateCommand.Parameters; sqlParams.Add(ORDERID_PARM, SqlDbType.Int, 0, ORDERID_FIELD); sqlParams.Add(PRODUCTID_PARM, SqlDbType.Int, 0, PRODUCTID_FIELD);
sqlParams.Add(UNITPRICE_PARM, SqlDbType.Money, 0, UNITPRICE_FIELD); sqlParams.Add(QUANTITY_PARM, SqlDbType.SmallInt, 0, QUANTITY_FIELD); sqlParams.Add(DISCOUNT_PARM, SqlDbType.Real, 0, DISCOUNT_FIELD); daOrderDetail.UpdateCommand = updateCommand; // Fill the parent and child table. daOrder.Fill(dtOrder); daOrderDetail.Fill(dtOrderDetail); // Bind the default view of the order table to the grid. dataGrid.DataSource = dtOrder.DefaultView; } private void updateButton_Click(object sender, System.EventArgs e) { // Update order and order details tables. daOrderDetail.Update(ds.Tables[ORDERDETAILS_TABLE].Select(null, null, DataViewRowState.Deleted)); daOrder.Update(ds.Tables[ORDERS_TABLE].Select(null, null, DataViewRowState.Deleted)); daOrder.Update(ds.Tables[ORDERS_TABLE].Select(null, null, DataViewRowState.ModifiedCurrent)); daOrder.Update(ds.Tables[ORDERS_TABLE].Select(null, null, DataViewRowState.Added)); daOrderDetail.Update(ds.Tables[ORDERDETAILS_TABLE].Select(null, null, DataViewRowState.ModifiedCurrent)); daOrderDetail.Update(ds.Tables[ORDERDETAILS_TABLE].Select(null, null, DataViewRowState.Added)); } Discussion The DataGrid control can display a single DataTable or a DataSet containing a set of DataTable objects with a hierarchical relationship between them. The DataGrid provides a user interface for the data, navigation between related tables as well as formatting and editing capabilities. If a DataGrid is bound to a DataSet containing related tables, and navigation is enabled for the DataGrid, expanders will be displayed for each row that has a child relationship. The DataGrid must be bound to a data source using its DataSource and DataMember properties at design time, or by using the DataSource property or SetBindingMethod( ) at runtime. Valid data sources for the DataGrid include DataTable, DataSet, DataView, and
DataViewManager objects. The DataGrid control dynamically reflects any changes made to the data source. If the ReadOnly property of the DataGrid is set to false, the data source is updated when changes are made to data in the DataGrid. This automatic update happens when the field being edited changes or when the EndEdit( ) method is called on the data source for the DataGrid. The data object that is bound to the DataGrid is responsible for updating the underlying data source. [ Team LiB ]