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http://code.msdn.microsoft.com/CSADONETDataServiceClient-aaeafce9/sourcecode?fileId=21609&pathId=2048894653

 

/****************************** Module Header ******************************\ * Module Name: SchoolLinqToEntities.svc.cs * Project: CSADONETDataService * Copyright (c) Microsoft Corporation. * * SchoolLinqToEntities.svc demonstrates the ADO.NET Data Service for ADO.NET * Entity Data Model. The ADO.NET Entity Data Model connects to the SQL * Server database deployed by SQLServer2005DB. It contains data tables: * Person, Course, CourseGrade, and CourseInstructor. The service also exports * a service operation CoursesByPersonID to retrieve the instructor's Course * list by PersonID, a service operation GetPersonUpdateException to get the * person update exception, a service query interceptor to filter the Course * objects, and a servie change interceptor to check PersonCategory value of * Added or Changed Person objects. * * * This source is subject to the Microsoft Public License. * See http://www.microsoft.com/opensource/licenses.mspx#Ms-PL. * All other rights reserved. * * THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, * EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE. \***************************************************************************/ #region Using directive using System; using System.Collections.Generic; using System.Data.Services; using System.Linq; using System.ServiceModel.Web; using System.Web; using CSADONETDataService.LinqToEntities; using System.Linq.Expressions; #endregion namespace CSADONETDataService { public class SchoolLinqToEntities : DataService<SQLServer2005DBEntities> { // This method is called only once to initialize service-wide policies. public static void InitializeService(IDataServiceConfiguration config) { // Set rules to indicate which entity sets and service operations // are visible, updatable, etc. config.UseVerboseErrors = true; config.SetEntitySetAccessRule("*", EntitySetRights.All); config.SetServiceOperationAccessRule("CoursesByPersonID", ServiceOperationRights.All); config.SetServiceOperationAccessRule("GetPersonUpdateException", ServiceOperationRights.All); } /// <summary> /// Override the HandleException method to throw 400 Bad Request /// exception to the client side. /// </summary> /// <param name="args">The HandleException argument</param> protected override void HandleException(HandleExceptionArgs args) { // Check if the InnerException is null if (args.Exception.InnerException != null) { // Convert the InnerException to DataServiceException DataServiceException ex = args.Exception.InnerException as DataServiceException; // Check if the InnerException is in type of // DataServiceException and the StatusCode is // 400(Bad Request) if (ex != null && ex.StatusCode == 400) { // Return the DataServiceException to the client args.Exception = ex; } } base.HandleException(args); } /// <summary> /// A service operation that retrieve the person update exception /// information /// </summary> /// <returns>An IQueryable collection contains Person objects /// </returns> [WebGet] public IQueryable<Person> GetPersonUpdateException() { // Throw the person update exception to the client throw new DataServiceException(400, "The valid value of PersonCategory is 1" + "(for students) or 2(for instructors)."); ; } /// <summary> /// A service operation that retrieve the instructor's courses list /// by primary key PersonID /// </summary> /// <param name="ID">The primary key PersonID</param> /// <returns>An IQueryable collection contains Course objects /// </returns> [WebGet] public IQueryable<Course> CoursesByPersonID(int ID) { // Check whether the PersonID is valid and it is instructor's ID if (this.CurrentDataSource.Person.Any(i => i.PersonID == ID && i.PersonCategory == 2)) { // Retrieve the instructor's course list var courses = from p in this.CurrentDataSource.Person where p.PersonID == ID select p.Course; // Return the query result return courses.First().AsQueryable(); } else { // Throw DataServiceException if the PersonID is invalid or // it is student's ID throw new DataServiceException(400, "Person ID is incorrect" + " or the person is not instructor!"); } } /// <summary> /// A service query interceptor that filters the course objects to /// return the course which CourseID is larger than 4000 /// </summary> /// <returns>LINQ lambda expression to filter the course objects /// </returns> [QueryInterceptor("Course")] public Expression<Func<Course, bool>> QueryCourse() { // LINQ lambda expression to filter the course objects return c => c.CourseID > 4000; } /// <summary> /// A service change interceptor that checks the PersonCategory value /// of the added or changed Person object /// </summary> /// <param name="p">The added or changed Person object</param> /// <param name="operation">The update operation</param> [ChangeInterceptor("Person")] public void OnChangePerson(Person p, UpdateOperations operation) { // Check whether the update operation is Add or Change if (operation == UpdateOperations.Add || operation == UpdateOperations.Change) { // Check invalid value of PersonCategory if (p.PersonCategory != 1 && p.PersonCategory != 2) { // Throw DataServieException throw new DataServiceException(400, "The valid value of PersonCategory is 1" + "(for students) or 2(for instructors).");; } } } } }