CHAPTER 1 ■ CREATE CLOUD TABLE STORAGE 8 City = city; State = (int)state; Zip = zip; County = county; Country = country; } } 4. In the same project, create a folder called CloudDataService. Add three interface definitions—IDataTableService, IHasDependencyTableService, and INoDependencyTableService—to this folder. The interface IDataTableService exposes three basic data table access functions: Insert, Update, and Delete. All these functions accept a parameter of type TableStorageEntity defined in the Microsoft.Samples.ServiceHosting.StorageClient namespace. The two other interfaces are derived from the interface IDataTableService. The interface IHasDependencyTableService exposes one method, UpdateDependencyTable(), which also accepts a parameter of type TableStorageEntity. The third interface, INoDependency, does not expose any methods but provides a type definition used for marking a class as having no logical dependency data object. 5. Add two classes into the folder CloudDataServices—DataTableService and AddressTableService. Mark the first class as an abstract class. The AddressTableService class is a derived class from the DataTableService class and implements the interface INoDependencyTableService. In the base class DataTableService, all three basic data I/O methods—Insert, Update, and Delete—are implemented. The Insert and Delete methods are marked as virtual, allowing concrete classes derived from this base class to override them. The implementation for all interfaces and classes is shown in Listing 1-4. Listing 1-4. Implementation for All Interfaces and Classes Defined in the Folder CloudDataServices using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace CreateDataStorage.Models.CloudDataServices { using Microsoft.Samples.ServiceHosting.StorageClient; public interface IDataTableService { bool Insert(TableStorageEntity entity); bool Update(TableStorageEntity entity); bool Delete(TableStorageEntity entity); } public interface IHasDependencyTableService : IDataTableService { bool UpdateDependencyTable(TableStorageEntity entity); } CHAPTER 1 ■ CREATE CLOUD TABLE STORAGE 9 public interface INoDependencyTableService : IDataTableService { } } using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace CreateDataStorage.Models.CloudDataServices { using Microsoft.Samples.ServiceHosting.StorageClient; using CreateDataStorage.Models.CloudDataContext; abstract public class DataTableService { protected UserDataContext userDataContext = null; protected string Table { get; set; } public DataTableService() { userDataContext = new UserDataContext(); } public UserDataContext DataContext() { return userDataContext; } virtual public bool Insert(TableStorageEntity entity) { bool success = false; try { if (this is IHasDependencyTableService) { (this as IHasDependencyTableService).UpdateDependencyTable(entity); } userDataContext.AddObject( Table, entity); userDataContext.SaveChanges(); success = true; } catch { } return success; } public bool Update(TableStorageEntity entity) { bool success = false; try CHAPTER 1 ■ CREATE CLOUD TABLE STORAGE 10 { if (Delete(entity)) { success = Insert(entity); } } catch { } return success; } virtual public bool Delete(TableStorageEntity entity) { bool success = false; try { if (this is IHasDependencyTableService) { (this as IHasDependencyTableService).UpdateDependencyTable(entity); } userDataContext.DeleteObject(entity); userDataContext.SaveChanges(); success = true; } catch { } return success; } } } using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Configuration; namespace CreateDataStorage.Models.CloudDataServices { using Microsoft.Samples.ServiceHosting.StorageClient; using CreateDataStorage.Models.CloudData; public class AddressTableService : DataTableService, INoDependencyTableService { public AddressTableService() { Table = ConfigurationManager.AppSettings["AddressTable"]; } } } CHAPTER 1 ■ CREATE CLOUD TABLE STORAGE 11 6. In the same project, add the class UserDataContext, derived from the Azure SDK base class TableStorageDataServiceContext. This class encapsulates a cloud storage query function as Listing 1-5 shows. Listing 1-5. Class UserDataContext Definition public class UserDataContext : TableStorageDataServiceContext { public DataServiceQuery<Address> AddressTable { get { return CreateQuery<Address>(ConfigurationManager.AppSettings["AddressTable"]); } } } 7. Right-click on the CreateDataStorage project node in the Solution Explorer panel to bring up the Property dialog box. Select Development in the left pane. Enter the database name, AzureForDotNetDeveloper, into the dialog box, as Figure 1-4 shows. Figure 1-4. Enter data table name 8. Add a reference to CloudData.Models.dll to the CloudStorageService WorkerRole project. 9. Right-click on the CreateDataStorage project and select Create Test Storage Table as Figure 1-5 shows. The compiler will analyze the code and generate a table for the database. The generated table in the database is shown in Figure 1-6. CHAPTER 1 ■ CREATE CLOUD TABLE STORAGE 12 Figure 1-5. Generate SQL storage Figure 1-6. Data table has been generated in local SQL database . INoDependencyTableService { public AddressTableService() { Table = ConfigurationManager.AppSettings["AddressTable"]; } } } CHAPTER 1 ■ CREATE CLOUD TABLE STORAGE 11 6 DataServiceQuery<Address> AddressTable { get { return CreateQuery<Address>(ConfigurationManager.AppSettings["AddressTable"]); } } } 7. Right-click on the CreateDataStorage project