Đang chuẩn bị liên kết để tải về tài liệu:
Filtering and Sorting Data

[ Team LiB ] Recipe 3.1 Filtering and Sorting Data Problem You have a DataSet filled with data, but you need to work with only a subset of the records and also to sort them. You need a way to both filter and sort the records in your DataSet without requerying the data source. | Team LiB Recipe 3.1 Filtering and Sorting Data Problem You have a DataSet filled with data but you need to work with only a subset of the records and also to sort them. You need a way to both filter and sort the records in your DataSet without requerying the data source. Solution Use DataViewManager and DataView objects to filter and sort a DataSet. The sample code contains two event handlers Form.Load Sets up the sample by creating a DataSet containing the Customers and Orders tables from the Northwind sample database and a relation between them. The default view for the Customers table is bound to the data grid on the form. Refresh Button.Click Applies the filters and sort order specified by the user to the data views for the tables accessed through the DataViewManager object. The C code is shown in Example 3-1. Example 3-1. File FilterSortForm.cs Namespaces variables and constants using System using System.Configuration using System.Data using System.Data.SqlClient Table name constants private const String CUSTOMERS_TABLE Customers private const String ORDERS_TABLE Orders Relation name constants private const String CUSTOMERS_ORDERS_RELATION Customers_Orders_Relation Field name constants private const String CUSTOMERID_FIELD CustomerlD private const String ORDERID_FIELD OrderlD private const String CONTACTNAME_FIELD ContactName private DataSet ds . . . private void FilterSortForm_Load object sender System.EventArgs e ds new DataSet SqlDataAdapter da Fill the Customers table and add it to the DataSet. da new SqlDataAdapter SELECT FROM Customers ConfigurationSettings.AppSettings S ql_ConnectString DataTable customersTable new DataTable CUSTOMERS_TABLE da.Fill customersTable ds.Tables.Add customersTable Fill the Order table and add it to the DataSet. da new SqlDataAdapter SELECT FROM Orders ConfigurationSettings.AppSettings S ql_ConnectString DataTable orderTable new DataTable ORDERS_TABLE da.Fill orderTable ds.Tables.Add orderTable Create a relation between the .