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Looking ahead at 2011-with Gartner

- by andrea.mulder

Speaking of forecasting the future. Gartner highlighted the top 10 technologies and trends that will be strategic for most organizations in 2011. While Gartner's predictions are not specific to CRM, you just cannot help but notice some of the common themes in store for 2011. The top 10 strategic technologies for 2011 include: Cloud Computing Mobile Applications and Media Tablets Social Communications and Collaborations Video Next Generation Analytics Social Analytics Context-Aware Computing Storage Class Memory Ubiquitous Computing Fabric-Based Infrastructure and Computers

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Passing multiple simple POST Values to ASP.NET Web API

- by Rick Strahl

A few weeks backs I posted a blog post about what does and doesn't work with ASP.NET Web API when it comes to POSTing data to a Web API controller. One of the features that doesn't work out of the box - somewhat unexpectedly - is the ability to map POST form variables to simple parameters of a Web API method. For example imagine you have this form and you want to post this data to a Web API end point like this via AJAX: <form> Name: <input type="name" name="name" value="Rick" /> Value: <input type="value" name="value" value="12" /> Entered: <input type="entered" name="entered" value="12/01/2011" /> <input type="button" id="btnSend" value="Send" /> </form> <script type="text/javascript"> $("#btnSend").click( function() { $.post("samples/PostMultipleSimpleValues?action=kazam", $("form").serialize(), function (result) { alert(result); }); }); </script> or you might do this more explicitly by creating a simple client map and specifying the POST values directly by hand:$.post("samples/PostMultipleSimpleValues?action=kazam", { name: "Rick", value: 1, entered: "12/01/2012" }, $("form").serialize(), function (result) { alert(result); }); On the wire this generates a simple POST request with Url Encoded values in the content:POST /AspNetWebApi/samples/PostMultipleSimpleValues?action=kazam HTTP/1.1 Host: localhost User-Agent: Mozilla/5.0 (Windows NT 6.2; WOW64; rv:15.0) Gecko/20100101 Firefox/15.0.1 Accept: application/json Connection: keep-alive Content-Type: application/x-www-form-urlencoded; charset=UTF-8 X-Requested-With: XMLHttpRequest Referer: http://localhost/AspNetWebApi/FormPostTest.html Content-Length: 41 Pragma: no-cache Cache-Control: no-cachename=Rick&value=12&entered=12%2F10%2F2011 Seems simple enough, right? We are basically posting 3 form variables and 1 query string value to the server. Unfortunately Web API can't handle request out of the box. If I create a method like this:[HttpPost] public string PostMultipleSimpleValues(string name, int value, DateTime entered, string action = null) { return string.Format("Name: {0}, Value: {1}, Date: {2}, Action: {3}", name, value, entered, action); }You'll find that you get an HTTP 404 error and { "Message": "No HTTP resource was found that matches the request URI…"} Yes, it's possible to pass multiple POST parameters of course, but Web API expects you to use Model Binding for this - mapping the post parameters to a strongly typed .NET object, not to single parameters. Alternately you can also accept a FormDataCollection parameter on your API method to get a name value collection of all POSTed values. If you're using JSON only, using the dynamic JObject/JValue objects might also work. ModelBinding is fine in many use cases, but can quickly become overkill if you only need to pass a couple of simple parameters to many methods. Especially in applications with many, many AJAX callbacks the 'parameter mapping type' per method signature can lead to serious class pollution in a project very quickly. Simple POST variables are also commonly used in AJAX applications to pass data to the server, even in many complex public APIs. So this is not an uncommon use case, and - maybe more so a behavior that I would have expected Web API to support natively. The question "Why aren't my POST parameters mapping to Web API method parameters" is already a frequent one… So this is something that I think is fairly important, but unfortunately missing in the base Web API installation. Creating a Custom Parameter Binder Luckily Web API is greatly extensible and there's a way to create a custom Parameter Binding to provide this functionality! Although this solution took me a long while to find and then only with the help of some folks Microsoft (thanks Hong Mei!!!), it's not difficult to hook up in your own projects. It requires one small class and a GlobalConfiguration hookup. Web API parameter bindings allow you to intercept processing of individual parameters - they deal with mapping parameters to the signature as well as converting the parameters to the actual values that are returned. Here's the implementation of the SimplePostVariableParameterBinding class:public class SimplePostVariableParameterBinding : HttpParameterBinding { private const string MultipleBodyParameters = "MultipleBodyParameters"; public SimplePostVariableParameterBinding(HttpParameterDescriptor descriptor) : base(descriptor) { } /// <summary> /// Check for simple binding parameters in POST data. Bind POST /// data as well as query string data /// </summary> public override Task ExecuteBindingAsync(ModelMetadataProvider metadataProvider, HttpActionContext actionContext, CancellationToken cancellationToken) { // Body can only be read once, so read and cache it NameValueCollection col = TryReadBody(actionContext.Request); string stringValue = null; if (col != null) stringValue = col[Descriptor.ParameterName]; // try reading query string if we have no POST/PUT match if (stringValue == null) { var query = actionContext.Request.GetQueryNameValuePairs(); if (query != null) { var matches = query.Where(kv => kv.Key.ToLower() == Descriptor.ParameterName.ToLower()); if (matches.Count() > 0) stringValue = matches.First().Value; } } object value = StringToType(stringValue); // Set the binding result here SetValue(actionContext, value); // now, we can return a completed task with no result TaskCompletionSource<AsyncVoid> tcs = new TaskCompletionSource<AsyncVoid>(); tcs.SetResult(default(AsyncVoid)); return tcs.Task; } private object StringToType(string stringValue) { object value = null; if (stringValue == null) value = null; else if (Descriptor.ParameterType == typeof(string)) value = stringValue; else if (Descriptor.ParameterType == typeof(int)) value = int.Parse(stringValue, CultureInfo.CurrentCulture); else if (Descriptor.ParameterType == typeof(Int32)) value = Int32.Parse(stringValue, CultureInfo.CurrentCulture); else if (Descriptor.ParameterType == typeof(Int64)) value = Int64.Parse(stringValue, CultureInfo.CurrentCulture); else if (Descriptor.ParameterType == typeof(decimal)) value = decimal.Parse(stringValue, CultureInfo.CurrentCulture); else if (Descriptor.ParameterType == typeof(double)) value = double.Parse(stringValue, CultureInfo.CurrentCulture); else if (Descriptor.ParameterType == typeof(DateTime)) value = DateTime.Parse(stringValue, CultureInfo.CurrentCulture); else if (Descriptor.ParameterType == typeof(bool)) { value = false; if (stringValue == "true" || stringValue == "on" || stringValue == "1") value = true; } else value = stringValue; return value; } /// <summary> /// Read and cache the request body /// </summary> /// <param name="request"></param> /// <returns></returns> private NameValueCollection TryReadBody(HttpRequestMessage request) { object result = null; // try to read out of cache first if (!request.Properties.TryGetValue(MultipleBodyParameters, out result)) { // parsing the string like firstname=Hongmei&lastname=Ge result = request.Content.ReadAsFormDataAsync().Result; request.Properties.Add(MultipleBodyParameters, result); } return result as NameValueCollection; } private struct AsyncVoid { } } The ExecuteBindingAsync method is fired for each parameter that is mapped and sent for conversion. This custom binding is fired only if the incoming parameter is a simple type (that gets defined later when I hook up the binding), so this binding never fires on complex types or if the first type is not a simple type. For the first parameter of a request the Binding first reads the request body into a NameValueCollection and caches that in the request.Properties collection. The request body can only be read once, so the first parameter request reads it and then caches it. Subsequent parameters then use the cached POST value collection. Once the form collection is available the value of the parameter is read, and the value is translated into the target type requested by the Descriptor. SetValue writes out the value to be mapped. Once you have the ParameterBinding in place, the binding has to be assigned. This is done along with all other Web API configuration tasks at application startup in global.asax's Application_Start:GlobalConfiguration.Configuration.ParameterBindingRules .Insert(0, (HttpParameterDescriptor descriptor) => { var supportedMethods = descriptor.ActionDescriptor.SupportedHttpMethods; // Only apply this binder on POST and PUT operations if (supportedMethods.Contains(HttpMethod.Post) || supportedMethods.Contains(HttpMethod.Put)) { var supportedTypes = new Type[] { typeof(string), typeof(int), typeof(decimal), typeof(double), typeof(bool), typeof(DateTime) }; if (supportedTypes.Where(typ => typ == descriptor.ParameterType).Count() > 0) return new SimplePostVariableParameterBinding(descriptor); } // let the default bindings do their work return null; }); The ParameterBindingRules.Insert method takes a delegate that checks which type of requests it should handle. The logic here checks whether the request is POST or PUT and whether the parameter type is a simple type that is supported. Web API calls this delegate once for each method signature it tries to map and the delegate returns null to indicate it's not handling this parameter, or it returns a new parameter binding instance - in this case the SimplePostVariableParameterBinding. Once the parameter binding and this hook up code is in place, you can now pass simple POST values to methods with simple parameters. The examples I showed above should now work in addition to the standard bindings. Summary Clearly this is not easy to discover. I spent quite a bit of time digging through the Web API source trying to figure this out on my own without much luck. It took Hong Mei at Micrsoft to provide a base example as I asked around so I can't take credit for this solution :-). But once you know where to look, Web API is brilliantly extensible to make it relatively easy to customize the parameter behavior. I'm very stoked that this got resolved - in the last two months I've had two customers with projects that decided not to use Web API in AJAX heavy SPA applications because this POST variable mapping wasn't available. This might actually change their mind to still switch back and take advantage of the many great features in Web API. I too frequently use plain POST variables for communicating with server AJAX handlers and while I could have worked around this (with untyped JObject or the Form collection mostly), having proper POST to parameter mapping makes things much easier. I said this in my last post on POST data and say it again here: I think POST to method parameter mapping should have been shipped in the box with Web API, because without knowing about this limitation the expectation is that simple POST variables map to parameters just like query string values do. I hope Microsoft considers including this type of functionality natively in the next version of Web API natively or at least as a built-in HttpParameterBinding that can be just added. This is especially true, since this binding doesn't affect existing bindings. Resources SimplePostVariableParameterBinding Source on GitHub Global.asax hookup source Mapping URL Encoded Post Values in ASP.NET Web API© Rick Strahl, West Wind Technologies, 2005-2012Posted in Web Api AJAX Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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BSON Serialization

BSON is a binary-encoded serialization of JSON-like documents, which essentially means its an efficient way of transfering information. Part of my work on the MongoDB NoRM drivers, discussed in more details by Rob Conery, is to write an efficient and maintainable BSON serializer and deserializer. The goal of the serializer is that you give it a .NET object and you get a byte array out of it which represents valid BSON. The deserializer does the opposite - give it a byte array and out pops your object....Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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Getting MySQL work with Entity Framework 4.0

- by DigiMortal

Does MySQL work with Entity Framework 4.0? The answer is: yes, it works! I just put up one experimental project to play with MySQL and Entity Framework 4.0 and in this posting I will show you how to get MySQL data to EF. Also I will give some suggestions how to deploy your applications to hosting and cloud environments. MySQL stuff As you may guess you need MySQL running somewhere. I have MySQL installed to my development machine so I can also develop stuff when I’m offline. The other thing you need is MySQL Connector for .NET Framework. Currently there is available development version of MySQL Connector/NET 6.3.5 that supports Visual Studio 2010. Before you start download MySQL and Connector/NET: MySQL Community Server Connector/NET 6.3.5 If you are not big fan of phpMyAdmin then you can try out free desktop client for MySQL – HeidiSQL. I am using it and I am really happy with this program. NB! If you just put up MySQL then create also database with couple of table there. To use all features of Entity Framework 4.0 I suggest you to use InnoDB or other engine that has support for foreign keys. Connecting MySQL to Entity Framework 4.0 Now create simple console project using Visual Studio 2010 and go through the following steps. 1. Add new ADO.NET Entity Data Model to your project. For model insert the name that is informative and that you are able later recognize. Now you can choose how you want to create your model. Select “Generate from database” and click OK. 2. Set up database connection Change data connection and select MySQL Database as data source. You may also need to set provider – there is only one choice. Select it if data provider combo shows empty value. Click OK and insert connection information you are asked about. Don’t forget to click test connection button to see if your connection data is okay. If everything works then click OK. 3. Insert context name Now you should see the following dialog. Insert your data model name for application configuration file and click OK. Click next button. 4. Select tables for model Now you can select tables and views your classes are based on. I have small database with events data. Uncheck the checkbox “Include foreign key columns in the model” – it is damn annoying to get them away from model later. Also insert informative and easy to remember name for your model. Click finish button. 5. Define your classes Now it’s time to define your classes. Here you can see what Entity Framework generated for you. Relations were detected automatically – that’s why we needed foreign keys. The names of classes and their members are not nice yet. After some modifications my class model looks like on the following diagram. Note that I removed attendees navigation property from person class. Now my classes look nice and they follow conventions I am using when naming classes and their members. NB! Don’t forget to see properties of classes (properties windows) and modify their set names if set names contain numbers (I changed set name for Entity from Entity1 to Entities). 6. Let’s test! Now let’s write simple testing program to see if MySQL data runs through Entity Framework 4.0 as expected. My program looks for events where I attended. using(var context = new MySqlEntities()) { var myEvents = from e in context.Events from a in e.Attendees where a.Person.FirstName == "Gunnar" && a.Person.LastName == "Peipman" select e; Console.WriteLine("My events: "); foreach(var e in myEvents) { Console.WriteLine(e.Title); } } Console.ReadKey(); And when I run it I get the result shown on screenshot on right. I checked out from database and these results are correct. At first run connector seems to work slow but this is only the effect of first run. As connector is loaded to memory by Entity Framework it works fast from this point on. Now let’s see what we have to do to get our program work in hosting and cloud environments where MySQL connector is not installed. Deploying application to hosting and cloud environments If your hosting or cloud environment has no MySQL connector installed you have to provide MySQL connector assemblies with your project. Add the following assemblies to your project’s bin folder and include them to your project (otherwise they are not packaged by WebDeploy and Azure tools): MySQL.Data MySQL.Data.Entity MySQL.Web You can also add references to these assemblies and mark references as local so these assemblies are copied to binary folder of your application. If you have references to these assemblies then you don’t have to include them to your project from bin folder. Also add the following block to your application configuration file. <?xml version="1.0" encoding="utf-8"?> <configuration> ... <system.data> <DbProviderFactories> <add name=”MySQL Data Provider” invariant=”MySql.Data.MySqlClient” description=”.Net Framework Data Provider for MySQL” type=”MySql.Data.MySqlClient.MySqlClientFactory, MySql.Data, Version=6.2.0.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d” /> </DbProviderFactories> </system.data> ... </configuration> Conclusion It was not hard to get MySQL connector installed and MySQL connected to Entity Framework 4.0. To use full power of Entity Framework we used InnoDB engine because it supports foreign keys. It was also easy to query our model. To get our project online we needed some easy modifications to our project and configuration files.

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SQL SERVER – 4 Tips for ETL Software IDE Developers

- by pinaldave

In a previous blog, I introduced the notion of Semantic Types. To an end-user, a seamlessly integrated semantic typing engine significantly increases the ease of use of an ETL IDE (integrated development environment, or developer studio). This led me to think about other ease-of-use issues I have encountered while building ETL applications. When I get stumped while programming, I find myself asking the variations on these questions: “How do I…?” “Now what?” “Why isn’t this working?” “Why do I have to redo the work I just did?” It seems to me that a good ETL IDE will anticipate these questions and seek to answer them before they are even asked. So here are my tips to help software vendors build developer IDEs that actually make development easier. How do I…? While developing an ETL application, have you ever asked yourself: “How do I set up the connection to my SQL Server database?”,“How do I import my table definitions from Access?”, etc. An easy answer might be “read the manual” but sometimes product manuals are not robust or easily accessible. So, integrating robust how-to instructions directly into your ETLstudio would help users get the information they need at the time they need it. Now what? IDEs in general know where you last clicked or performed an action using an input device such as a keyboard; so they should be able to reasonably predict the design context you are in and suggest the next steps accordingly. Context-sensitive suggestions based on the state of the user’s work will help users move forward in ETL application development. Why isn’t this working? Or why do I have to wait till I compile to be told about a critical design issue? If an ETL IDE is smart enough to signal to users what in their design structures is left to be completed or has been completed incorrectly, then the developer can spend much less time in the designàcompileàerror-correct loop. Just-in-time validation helps users detect and correct programming errors earlier in the ETL development life cycle. Why do I have to redo the work I just did? In ETL development, schemas, transformation rules, connectivity objects, etc., can be reused in various situations. Using mouse-clicks to build and manage libraries of reusable design objects implies that the application development effort should decrease over time and as the library acquires more objects. I met a great company at SQL Pass that is trying to address many of these usability issues. Check them out at www.expressor-software.com. What other ease-of-use suggestions do you have for ETL software vendors? Please post your valuable comments. ?Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Best Practices, Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: ETL

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Developing web apps using ASP.NET MVC 3, Razor and EF Code First - Part 1

- by shiju

In this post, I will demonstrate web application development using ASP. NET MVC 3, Razor and EF code First. This post will also cover Dependency Injection using Unity 2.0 and generic Repository and Unit of Work for EF Code First. The following frameworks will be used for this step by step tutorial. ASP.NET MVC 3 EF Code First CTP 5 Unity 2.0 Define Domain Model Let’s create domain model for our simple web application Category class public class Category { public int CategoryId { get; set; } [Required(ErrorMessage = "Name Required")] [StringLength(25, ErrorMessage = "Must be less than 25 characters")] public string Name { get; set;} public string Description { get; set; } public virtual ICollection<Expense> Expenses { get; set; } } Expense class public class Expense { public int ExpenseId { get; set; } public string Transaction { get; set; } public DateTime Date { get; set; } public double Amount { get; set; } public int CategoryId { get; set; } public virtual Category Category { get; set; } } We have two domain entities - Category and Expense. A single category contains a list of expense transactions and every expense transaction should have a Category. In this post, we will be focusing on CRUD operations for the entity Category and will be working on the Expense entity with a View Model object in the later post. And the source code for this application will be refactored over time. The above entities are very simple POCO (Plain Old CLR Object) classes and the entity Category is decorated with validation attributes in the System.ComponentModel.DataAnnotations namespace. Now we want to use these entities for defining model objects for the Entity Framework 4. Using the Code First approach of Entity Framework, we can first define the entities by simply writing POCO classes without any coupling with any API or database library. This approach lets you focus on domain model which will enable Domain-Driven Development for applications. EF code first support is currently enabled with a separate API that is runs on top of the Entity Framework 4. EF Code First is reached CTP 5 when I am writing this article. Creating Context Class for Entity Framework We have created our domain model and let’s create a class in order to working with Entity Framework Code First. For this, you have to download EF Code First CTP 5 and add reference to the assembly EntitFramework.dll. You can also use NuGet to download add reference to EEF Code First. public class MyFinanceContext : DbContext { public MyFinanceContext() : base("MyFinance") { } public DbSet<Category> Categories { get; set; } public DbSet<Expense> Expenses { get; set; } } The above class MyFinanceContext is derived from DbContext that can connect your model classes to a database. The MyFinanceContext class is mapping our Category and Expense class into database tables Categories and Expenses using DbSet<TEntity> where TEntity is any POCO class. When we are running the application at first time, it will automatically create the database. EF code-first look for a connection string in web.config or app.config that has the same name as the dbcontext class. If it is not find any connection string with the convention, it will automatically create database in local SQL Express database by default and the name of the database will be same name as the dbcontext class. You can also define the name of database in constructor of the the dbcontext class. Unlike NHibernate, we don’t have to use any XML based mapping files or Fluent interface for mapping between our model and database. The model classes of Code First are working on the basis of conventions and we can also use a fluent API to refine our model. The convention for primary key is ‘Id’ or ‘<class name>Id’. If primary key properties are detected with type ‘int’, ‘long’ or ‘short’, they will automatically registered as identity columns in the database by default. Primary key detection is not case sensitive. We can define our model classes with validation attributes in the System.ComponentModel.DataAnnotations namespace and it automatically enforces validation rules when a model object is updated or saved. Generic Repository for EF Code First We have created model classes and dbcontext class. Now we have to create generic repository pattern for data persistence with EF code first. If you don’t know about the repository pattern, checkout Martin Fowler’s article on Repository Let’s create a generic repository to working with DbContext and DbSet generics. public interface IRepository<T> where T : class { void Add(T entity); void Delete(T entity); T GetById(long Id); IEnumerable<T> All(); } RepositoryBasse – Generic Repository class public abstract class RepositoryBase<T> where T : class { private MyFinanceContext database; private readonly IDbSet<T> dbset; protected RepositoryBase(IDatabaseFactory databaseFactory) { DatabaseFactory = databaseFactory; dbset = Database.Set<T>(); } protected IDatabaseFactory DatabaseFactory { get; private set; } protected MyFinanceContext Database { get { return database ?? (database = DatabaseFactory.Get()); } } public virtual void Add(T entity) { dbset.Add(entity); } public virtual void Delete(T entity) { dbset.Remove(entity); } public virtual T GetById(long id) { return dbset.Find(id); } public virtual IEnumerable<T> All() { return dbset.ToList(); } } DatabaseFactory class public class DatabaseFactory : Disposable, IDatabaseFactory { private MyFinanceContext database; public MyFinanceContext Get() { return database ?? (database = new MyFinanceContext()); } protected override void DisposeCore() { if (database != null) database.Dispose(); } } Unit of Work If you are new to Unit of Work pattern, checkout Fowler’s article on Unit of Work . According to Martin Fowler, the Unit of Work pattern "maintains a list of objects affected by a business transaction and coordinates the writing out of changes and the resolution of concurrency problems." Let’s create a class for handling Unit of Work public interface IUnitOfWork { void Commit(); } UniOfWork class public class UnitOfWork : IUnitOfWork { private readonly IDatabaseFactory databaseFactory; private MyFinanceContext dataContext; public UnitOfWork(IDatabaseFactory databaseFactory) { this.databaseFactory = databaseFactory; } protected MyFinanceContext DataContext { get { return dataContext ?? (dataContext = databaseFactory.Get()); } } public void Commit() { DataContext.Commit(); } } The Commit method of the UnitOfWork will call the commit method of MyFinanceContext class and it will execute the SaveChanges method of DbContext class. Repository class for Category In this post, we will be focusing on the persistence against Category entity and will working on other entities in later post. Let’s create a repository for handling CRUD operations for Category using derive from a generic Repository RepositoryBase<T>. public class CategoryRepository: RepositoryBase<Category>, ICategoryRepository { public CategoryRepository(IDatabaseFactory databaseFactory) : base(databaseFactory) { } } public interface ICategoryRepository : IRepository<Category> { } If we need additional methods than generic repository for the Category, we can define in the CategoryRepository. Dependency Injection using Unity 2.0 If you are new to Inversion of Control/ Dependency Injection or Unity, please have a look on my articles at http://weblogs.asp.net/shijuvarghese/archive/tags/IoC/default.aspx. I want to create a custom lifetime manager for Unity to store container in the current HttpContext. public class HttpContextLifetimeManager<T> : LifetimeManager, IDisposable { public override object GetValue() { return HttpContext.Current.Items[typeof(T).AssemblyQualifiedName]; } public override void RemoveValue() { HttpContext.Current.Items.Remove(typeof(T).AssemblyQualifiedName); } public override void SetValue(object newValue) { HttpContext.Current.Items[typeof(T).AssemblyQualifiedName] = newValue; } public void Dispose() { RemoveValue(); } } Let’s create controller factory for Unity in the ASP.NET MVC 3 application. public class UnityControllerFactory : DefaultControllerFactory { IUnityContainer container; public UnityControllerFactory(IUnityContainer container) { this.container = container; } protected override IController GetControllerInstance(RequestContext reqContext, Type controllerType) { IController controller; if (controllerType == null) throw new HttpException( 404, String.Format( "The controller for path '{0}' could not be found" + "or it does not implement IController.", reqContext.HttpContext.Request.Path)); if (!typeof(IController).IsAssignableFrom(controllerType)) throw new ArgumentException( string.Format( "Type requested is not a controller: {0}", controllerType.Name), "controllerType"); try { controller= container.Resolve(controllerType) as IController; } catch (Exception ex) { throw new InvalidOperationException(String.Format( "Error resolving controller {0}", controllerType.Name), ex); } return controller; } } Configure contract and concrete types in Unity Let’s configure our contract and concrete types in Unity for resolving our dependencies. private void ConfigureUnity() { //Create UnityContainer IUnityContainer container = new UnityContainer() .RegisterType<IDatabaseFactory, DatabaseFactory>(new HttpContextLifetimeManager<IDatabaseFactory>()) .RegisterType<IUnitOfWork, UnitOfWork>(new HttpContextLifetimeManager<IUnitOfWork>()) .RegisterType<ICategoryRepository, CategoryRepository>(new HttpContextLifetimeManager<ICategoryRepository>()); //Set container for Controller Factory ControllerBuilder.Current.SetControllerFactory( new UnityControllerFactory(container)); } In the above ConfigureUnity method, we are registering our types onto Unity container with custom lifetime manager HttpContextLifetimeManager. Let’s call ConfigureUnity method in the Global.asax.cs for set controller factory for Unity and configuring the types with Unity. protected void Application_Start() { AreaRegistration.RegisterAllAreas(); RegisterGlobalFilters(GlobalFilters.Filters); RegisterRoutes(RouteTable.Routes); ConfigureUnity(); } Developing web application using ASP.NET MVC 3 We have created our domain model for our web application and also have created repositories and configured dependencies with Unity container. Now we have to create controller classes and views for doing CRUD operations against the Category entity. Let’s create controller class for Category Category Controller public class CategoryController : Controller { private readonly ICategoryRepository categoryRepository; private readonly IUnitOfWork unitOfWork; public CategoryController(ICategoryRepository categoryRepository, IUnitOfWork unitOfWork) { this.categoryRepository = categoryRepository; this.unitOfWork = unitOfWork; } public ActionResult Index() { var categories = categoryRepository.All(); return View(categories); } [HttpGet] public ActionResult Edit(int id) { var category = categoryRepository.GetById(id); return View(category); } [HttpPost] public ActionResult Edit(int id, FormCollection collection) { var category = categoryRepository.GetById(id); if (TryUpdateModel(category)) { unitOfWork.Commit(); return RedirectToAction("Index"); } else return View(category); } [HttpGet] public ActionResult Create() { var category = new Category(); return View(category); } [HttpPost] public ActionResult Create(Category category) { if (!ModelState.IsValid) { return View("Create", category); } categoryRepository.Add(category); unitOfWork.Commit(); return RedirectToAction("Index"); } [HttpPost] public ActionResult Delete(int id) { var category = categoryRepository.GetById(id); categoryRepository.Delete(category); unitOfWork.Commit(); var categories = categoryRepository.All(); return PartialView("CategoryList", categories); } } Creating Views in Razor Now we are going to create views in Razor for our ASP.NET MVC 3 application. Let’s create a partial view CategoryList.cshtml for listing category information and providing link for Edit and Delete operations. CategoryList.cshtml @using MyFinance.Helpers; @using MyFinance.Domain; @model IEnumerable<Category> <table> <tr> <th>Actions</th> <th>Name</th> <th>Description</th> </tr> @foreach (var item in Model) { <tr> <td> @Html.ActionLink("Edit", "Edit",new { id = item.CategoryId }) @Ajax.ActionLink("Delete", "Delete", new { id = item.CategoryId }, new AjaxOptions { Confirm = "Delete Expense?", HttpMethod = "Post", UpdateTargetId = "divCategoryList" }) </td> <td> @item.Name </td> <td> @item.Description </td> </tr> } </table> <p> @Html.ActionLink("Create New", "Create") </p> The delete link is providing Ajax functionality using the Ajax.ActionLink. This will call an Ajax request for Delete action method in the CategoryCotroller class. In the Delete action method, it will return Partial View CategoryList after deleting the record. We are using CategoryList view for the Ajax functionality and also for Index view using for displaying list of category information. Let’s create Index view using partial view CategoryList Index.chtml @model IEnumerable<MyFinance.Domain.Category> @{ ViewBag.Title = "Index"; } <h2>Category List</h2> <script src="@Url.Content("~/Scripts/jquery.unobtrusive-ajax.min.js")" type="text/javascript"></script> <div id="divCategoryList"> @Html.Partial("CategoryList", Model) </div> We can call the partial views using Html.Partial helper method. Now we are going to create View pages for insert and update functionality for the Category. Both view pages are sharing common user interface for entering the category information. So I want to create an EditorTemplate for the Category information. We have to create the EditorTemplate with the same name of entity object so that we can refer it on view pages using @Html.EditorFor(model => model) . So let’s create template with name Category. Let’s create view page for insert Category information @model MyFinance.Domain.Category @{ ViewBag.Title = "Save"; } <h2>Create</h2> <script src="@Url.Content("~/Scripts/jquery.validate.min.js")" type="text/javascript"></script> <script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.min.js")" type="text/javascript"></script> @using (Html.BeginForm()) { @Html.ValidationSummary(true) <fieldset> <legend>Category</legend> @Html.EditorFor(model => model) <p> <input type="submit" value="Create" /> </p> </fieldset> } <div> @Html.ActionLink("Back to List", "Index") </div> ViewStart file In Razor views, we can add a file named _viewstart.cshtml in the views directory and this will be shared among the all views with in the Views directory. The below code in the _viewstart.cshtml, sets the Layout page for every Views in the Views folder. @{ Layout = "~/Views/Shared/_Layout.cshtml"; } Source Code You can download the source code from http://efmvc.codeplex.com/ . The source will be refactored on over time. Summary In this post, we have created a simple web application using ASP.NET MVC 3 and EF Code First. We have discussed on technologies and practices such as ASP.NET MVC 3, Razor, EF Code First, Unity 2, generic Repository and Unit of Work. In my later posts, I will modify the application and will be discussed on more things. Stay tuned to my blog for more posts on step by step application building.

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Good Open souce game engines for making MMO game

- by Call Me Dummy

I am interested in making a MMO game but I am not sure where to start. I am looking for an open source game engine which is simple to use and allows me to concentrate on the game design and architecture. I have some basic C,C++,C# knowledge. After lots of searching in google I was going to start out with Ogre3D but soon realized that it is a rendering engine and does not include physics engine. I have not tried it yet since in many forums it says they don't have a good documentation. So is there any good open source game engine good for fast game developing ? Some key features I want include basic requirements like collision detection, object to object collision detection, physics etc.

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Validating a linked item’s data template in Sitecore

- by Kyle Burns

I’ve been doing quite a bit of work in Sitecore recently and last week I encountered a situation that it appears many others have hit. I was working with a field that had been configured originally as a grouped droplink, but now needed to be updated to support additional levels of hierarchy in the folder structure. If you’ve done any work in Sitecore that statement makes sense, but if not it may seem a bit cryptic. Sitecore offers a number of different field types and a subset of these field types focus on providing links either to other items on the content tree or to content that is not stored in Sitecore. In the case of the grouped droplink, the field is configured with a “root” folder and each direct descendant of this folder is considered to be a header for a grouping of other items and displayed in a dropdown. A picture is worth a thousand words, so consider the following piece of a content tree: If I configure a grouped droplink field to use the “Current” folder as its datasource, the control that gets to my content author looks like this: This presents a nicely organized display and limits the user to selecting only the direct grandchildren of the folder root. It also presents the limitation that struck as we were thinking through the content architecture and how it would hold up over time – the authors cannot further organize content under the root folder because of the structure required for the dropdown to work. Over time, not allowing the hierarchy to go any deeper would prevent out authors from being able to organize their content in a way that it would be found when needed, so the grouped droplink data type was not going to fit the bill. I needed to look for an alternative data type that allowed for selection of a single item and limited my choices to descendants of a specific node on the content tree. After looking at the options available for links in Sitecore and considering them against each other, one option stood out as nearly perfect – the droptree. This field type stores its data identically to the droplink and allows for the selection of zero or one items under a specific node in the content tree. By changing my data template to use droptree instead of grouped droplink, the author is now presented with the following when selecting a linked item: Sounds great, but a did say almost perfect – there’s still one flaw. The code intended to display the linked item is expecting the selection to use a specific data template (or more precisely it makes certain assumptions about the fields that will be present), but the droptree does nothing to prevent the author from selecting a folder (since folders are items too) instead of one of the items contained within a folder. I looked to see if anyone had already solved this problem. I found many people discussing the problem, but the closest that I found to a solution was the statement “the best thing would probably be to create a custom validator” with no further discussion in regards to what this validator might look like. I needed to create my own validator to ensure that the user had not selected a folder. Since so many people had the same issue, I decided to make the validator as reusable as possible and share it here. The validator that I created inherits from StandardValidator. In order to make the validator more intuitive to developers that are familiar with the TreeList controls in Sitecore, I chose to implement the following parameters: ExcludeTemplatesForSelection – serves as a “deny list”. If the data template of the selected item is in this list it will not validate IncludeTemplatesForSelection – this can either be empty to indicate that any template not contained in the exclusion list is acceptable or it can contain the list of acceptable templates Now that I’ve explained the parameters and the purpose of the validator, I’ll let the code do the rest of the talking: 1: /// <summary> 2: /// Validates that a link field value meets template requirements 3: /// specified using the following parameters: 4: /// - ExcludeTemplatesForSelection: If present, the item being 5: /// based on an excluded template will cause validation to fail. 6: /// - IncludeTemplatesForSelection: If present, the item not being 7: /// based on an included template will cause validation to fail 8: /// 9: /// ExcludeTemplatesForSelection trumps IncludeTemplatesForSelection 10: /// if the same value appears in both lists. Lists are comma seperated 11: /// </summary> 12: [Serializable] 13: public class LinkItemTemplateValidator : StandardValidator 14: { 15: public LinkItemTemplateValidator() 16: { 17: } 18: 19: /// <summary> 20: /// Serialization constructor is required by the runtime 21: /// </summary> 22: /// <param name="info"></param> 23: /// <param name="context"></param> 24: public LinkItemTemplateValidator(SerializationInfo info, StreamingContext context) : base(info, context) { } 25: 26: /// <summary> 27: /// Returns whether the linked item meets the template 28: /// constraints specified in the parameters 29: /// </summary> 30: /// <returns> 31: /// The result of the evaluation. 32: /// </returns> 33: protected override ValidatorResult Evaluate() 34: { 35: if (string.IsNullOrWhiteSpace(ControlValidationValue)) 36: { 37: return ValidatorResult.Valid; // let "required" validation handle 38: } 39: 40: var excludeString = Parameters["ExcludeTemplatesForSelection"]; 41: var includeString = Parameters["IncludeTemplatesForSelection"]; 42: if (string.IsNullOrWhiteSpace(excludeString) && string.IsNullOrWhiteSpace(includeString)) 43: { 44: return ValidatorResult.Valid; // "allow anything" if no params 45: } 46: 47: Guid linkedItemGuid; 48: if (!Guid.TryParse(ControlValidationValue, out linkedItemGuid)) 49: { 50: return ValidatorResult.Valid; // probably put validator on wrong field 51: } 52: 53: var item = GetItem(); 54: var linkedItem = item.Database.GetItem(new ID(linkedItemGuid)); 55: 56: if (linkedItem == null) 57: { 58: return ValidatorResult.Valid; // this validator isn't for broken links 59: } 60: 61: var exclusionList = (excludeString ?? string.Empty).Split(','); 62: var inclusionList = (includeString ?? string.Empty).Split(','); 63: 64: if ((inclusionList.Length == 0 || inclusionList.Contains(linkedItem.TemplateName)) 65: && !exclusionList.Contains(linkedItem.TemplateName)) 66: { 67: return ValidatorResult.Valid; 68: } 69: 70: Text = GetText("The field \"{0}\" specifies an item which is based on template \"{1}\". This template is not valid for selection", GetFieldDisplayName(), linkedItem.TemplateName); 71: 72: return GetFailedResult(ValidatorResult.FatalError); 73: } 74: 75: protected override ValidatorResult GetMaxValidatorResult() 76: { 77: return ValidatorResult.FatalError; 78: } 79: 80: public override string Name 81: { 82: get { return @"LinkItemTemplateValidator"; } 83: } 84: } In this blog entry, I have shared some code that I found useful in solving a problem that seemed fairly common. Hopefully the next person that is looking for this answer finds it useful as well.

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NoSQL with RavenDB and ASP.NET MVC - Part 2

- by shiju

In my previous post, we have discussed on how to work with RavenDB document database in an ASP.NET MVC application. We have setup RavenDB for our ASP.NET MVC application and did basic CRUD operations against a simple domain entity. In this post, let’s discuss on domain entity with deep object graph and how to query against RavenDB documents using Indexes.Let's create two domain entities for our demo ASP.NET MVC appplication public class Category { public string Id { get; set; } [Required(ErrorMessage = "Name Required")] [StringLength(25, ErrorMessage = "Must be less than 25 characters")] public string Name { get; set;} public string Description { get; set; } public List<Expense> Expenses { get; set; } public Category() { Expenses = new List<Expense>(); } } public class Expense { public string Id { get; set; } public Category Category { get; set; } public string Transaction { get; set; } public DateTime Date { get; set; } public double Amount { get; set; } } We have two domain entities - Category and Expense. A single category contains a list of expense transactions and every expense transaction should have a Category.Let's create ASP.NET MVC view model for Expense transaction public class ExpenseViewModel { public string Id { get; set; } public string CategoryId { get; set; } [Required(ErrorMessage = "Transaction Required")] public string Transaction { get; set; } [Required(ErrorMessage = "Date Required")] public DateTime Date { get; set; } [Required(ErrorMessage = "Amount Required")] public double Amount { get; set; } public IEnumerable<SelectListItem> Category { get; set; } } Let's create a contract type for Expense Repository public interface IExpenseRepository { Expense Load(string id); IEnumerable<Expense> GetExpenseTransactions(DateTime startDate,DateTime endDate); void Save(Expense expense,string categoryId); void Delete(string id); } Let's create a concrete type for Expense Repository for handling CRUD operations. public class ExpenseRepository : IExpenseRepository { private IDocumentSession session; public ExpenseRepository() { session = MvcApplication.CurrentSession; } public Expense Load(string id) { return session.Load<Expense>(id); } public IEnumerable<Expense> GetExpenseTransactions(DateTime startDate, DateTime endDate) { //Querying using the Index name "ExpenseTransactions" //filtering with dates var expenses = session.LuceneQuery<Expense>("ExpenseTransactions") .WaitForNonStaleResults() .Where(exp => exp.Date >= startDate && exp.Date <= endDate) .ToArray(); return expenses; } public void Save(Expense expense,string categoryId) { var category = session.Load<Category>(categoryId); if (string.IsNullOrEmpty(expense.Id)) { //new expense transaction expense.Category = category; session.Store(expense); } else { //modifying an existing expense transaction var expenseToEdit = Load(expense.Id); //Copy values to expenseToEdit ModelCopier.CopyModel(expense, expenseToEdit); //set category object expenseToEdit.Category = category; } //save changes session.SaveChanges(); } public void Delete(string id) { var expense = Load(id); session.Delete<Expense>(expense); session.SaveChanges(); } } Insert/Update Expense Transaction The Save method is used for both insert a new expense record and modifying an existing expense transaction. For a new expense transaction, we store the expense object with associated category into document session object and load the existing expense object and assign values to it for editing a existing record. public void Save(Expense expense,string categoryId) { var category = session.Load<Category>(categoryId); if (string.IsNullOrEmpty(expense.Id)) { //new expense transaction expense.Category = category; session.Store(expense); } else { //modifying an existing expense transaction var expenseToEdit = Load(expense.Id); //Copy values to expenseToEdit ModelCopier.CopyModel(expense, expenseToEdit); //set category object expenseToEdit.Category = category; } //save changes session.SaveChanges(); } Querying Expense transactions public IEnumerable<Expense> GetExpenseTransactions(DateTime startDate, DateTime endDate) { //Querying using the Index name "ExpenseTransactions" //filtering with dates var expenses = session.LuceneQuery<Expense>("ExpenseTransactions") .WaitForNonStaleResults() .Where(exp => exp.Date >= startDate && exp.Date <= endDate) .ToArray(); return expenses; } The GetExpenseTransactions method returns expense transactions using a LINQ query expression with a Date comparison filter. The Lucene Query is using a index named "ExpenseTransactions" for getting the result set. In RavenDB, Indexes are LINQ queries stored in the RavenDB server and would be executed on the background and will perform query against the JSON documents. Indexes will be working with a lucene query expression or a set operation. Indexes are composed using a Map and Reduce function. Check out Ayende's blog post on Map/Reduce We can create index using RavenDB web admin tool as well as programmitically using its Client API. The below shows the screen shot of creating index using web admin tool. We can also create Indexes using Raven Cleint API as shown in the following code documentStore.DatabaseCommands.PutIndex("ExpenseTransactions", new IndexDefinition<Expense,Expense>() { Map = Expenses => from exp in Expenses select new { exp.Date } }); In the Map function, we used a Linq expression as shown in the following from exp in docs.Expensesselect new { exp.Date };We have not used a Reduce function for the above index. A Reduce function is useful while performing aggregate functions based on the results from the Map function. Indexes can be use with set operations of RavenDB.SET OperationsUnlike other document databases, RavenDB supports set based operations that lets you to perform updates, deletes and inserts to the bulk_docs endpoint of RavenDB. For doing this, you just pass a query to a Index as shown in the following commandDELETE http://localhost:8080/bulk_docs/ExpenseTransactions?query=Date:20100531The above command using the Index named "ExpenseTransactions" for querying the documents with Date filter and will delete all the documents that match the query criteria. The above command is equivalent of the following queryDELETE FROM ExpensesWHERE Date='2010-05-31' Controller & ActionsWe have created Expense Repository class for performing CRUD operations for the Expense transactions. Let's create a controller class for handling expense transactions. public class ExpenseController : Controller { private ICategoryRepository categoyRepository; private IExpenseRepository expenseRepository; public ExpenseController(ICategoryRepository categoyRepository, IExpenseRepository expenseRepository) { this.categoyRepository = categoyRepository; this.expenseRepository = expenseRepository; } //Get Expense transactions based on dates public ActionResult Index(DateTime? StartDate, DateTime? EndDate) { //If date is not passed, take current month's first and last dte DateTime dtNow; dtNow = DateTime.Today; if (!StartDate.HasValue) { StartDate = new DateTime(dtNow.Year, dtNow.Month, 1); EndDate = StartDate.Value.AddMonths(1).AddDays(-1); } //take last date of startdate's month, if endate is not passed if (StartDate.HasValue && !EndDate.HasValue) { EndDate = (new DateTime(StartDate.Value.Year, StartDate.Value.Month, 1)).AddMonths(1).AddDays(-1); } var expenses = expenseRepository.GetExpenseTransactions(StartDate.Value, EndDate.Value); if (Request.IsAjaxRequest()) { return PartialView("ExpenseList", expenses); } ViewData.Add("StartDate", StartDate.Value.ToShortDateString()); ViewData.Add("EndDate", EndDate.Value.ToShortDateString()); return View(expenses); } // GET: /Expense/Edit public ActionResult Edit(string id) { var expenseModel = new ExpenseViewModel(); var expense = expenseRepository.Load(id); ModelCopier.CopyModel(expense, expenseModel); var categories = categoyRepository.GetCategories(); expenseModel.Category = categories.ToSelectListItems(expense.Category.Id.ToString()); return View("Save", expenseModel); } // // GET: /Expense/Create public ActionResult Create() { var expenseModel = new ExpenseViewModel(); var categories = categoyRepository.GetCategories(); expenseModel.Category = categories.ToSelectListItems("-1"); expenseModel.Date = DateTime.Today; return View("Save", expenseModel); } // // POST: /Expense/Save // Insert/Update Expense Tansaction [HttpPost] public ActionResult Save(ExpenseViewModel expenseViewModel) { try { if (!ModelState.IsValid) { var categories = categoyRepository.GetCategories(); expenseViewModel.Category = categories.ToSelectListItems(expenseViewModel.CategoryId); return View("Save", expenseViewModel); } var expense=new Expense(); ModelCopier.CopyModel(expenseViewModel, expense); expenseRepository.Save(expense, expenseViewModel.CategoryId); return RedirectToAction("Index"); } catch { return View(); } } //Delete a Expense Transaction public ActionResult Delete(string id) { expenseRepository.Delete(id); return RedirectToAction("Index"); } } Download the Source - You can download the source code from http://ravenmvc.codeplex.com

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Coherence Based WebLogic Server Session Management

- by [email protected]

Specifications Supported Configurations WebLogic Server 10.3.2( or 10.3.1 ) Coherence 3.5.2/463 If you use other verion above, then please check the following matrix: WebLogic Server 9.2 MP1 Weblogic Server 10.3 WebLogic Smart Update Patch ID: AJQB Patch ID: 6W2W Minimum Coherence Release Level/MetaLink Patch ID 3.4.2 Patch 2-Patch ID:8429415 3.4.2 Patch6-Patch ID:11399293 Environment Variables %COHERENCE_HOME%: coherence installation directory %DOMAIN_HOME%: weblogic domain foler. Instructions We Will create to weblogic domains: domain_a, domain_b. To configure those domains with coherence-based session management . Then the changings of session variable value in one domain will propagate to another domain. Main Steps WebLogic Server create domain_a The process is ignored copy %COHERENCE_HOME%\lib\coherence.jar to %DOMAIN_HOME%\lib startup domain deploy %COHERENCE_HOME%\lib\coherence-web-spi.war as a Shared Library repeat step 1~4 at domain_b Coherence duplicate %COHERENCE_HOME%\bin\cache-server.cmd at the same folder and rename it to web-cache-server.cmd modify web-cache-server.cmd java -server -Xms512m -Xmx512m -cp %coherence_home%/lib/coherence.jar;%coherence_home%/lib/coherence-web-spi.war -Dtangosol.coherence.management.remote=true -Dtangosol.coherence.cacheconfig=WEB-INF/classes/session-cache-config.xml -Dtangosol.coherence.session.localstorage=true com.tangosol.net.DefaultCacheServer startup web-cache-server.cmd Testing develop a web app with OEPE or JDeveloper and implment functions: changing, viewing, listing session variables. ( or download sample codes here ) modify weblogic.xml with following content: <?xml version="1.0" encoding="UTF-8"?> <wls:weblogic-web-app xmlns:wls=http://xmlns.oracle.com/weblogic/weblogic-web-app xmlns:xsi=http://www.w3.org/2001/XMLSchema-instance xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd http://xmlns.oracle.com/weblogic/weblogic-web-app http://xmlns.oracle.com/weblogic/weblogic-web-app/1.0/weblogic-web-app.xsd"> <wls:weblogic-version>10.3.2</wls:weblogic-version> <wls:context-root>CoherenceWeb</wls:context-root> <wls:library-ref> <wls:library-name>coherence-web-spi</wls:library-name> <wls:specification-version>1.0.0.0</wls:specification-version> <wls:exact-match>true</wls:exact-match> </wls:library-ref> </wls:weblogic-web-app> deploy the web app to domain_a and domain_b change session varaible vlaue at domain_a and check whethe if changed at domain_b References Using Oracle Coherence*Web 3.4.2 with Oracle WebLogic Server 10gR3 Oracle Coherence*Web 3.4.2 with Oracle WebLogic Server 10gR3

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VSDB to SSDT Part 2 : SQL Server 2008 Server Project … with SSDT

- by Etienne Giust

With Visual Studio 2012 and the use of SSDT technology, there is only one type of database project : SQL Server Database Project. With Visual Studio 2010, we used to have SQL Server 2008 Server Project which we used to define server-level objects, mostly logins and linked servers. A convenient wizard allowed for creation of this type of projects. It does not exists anymore. Here is how to create an equivalent of the SQL Server 2008 Server Project with Visual Studio 2012: Create a new SQL Server Database Project : it will be created empty Create a new SQL Schema Compare ( SQL menu item > Schema Compare > New Schema Comparison ) As a source, select any database on the SQL server you want to mimic Set the target to be your newly Database Project In the Schema Compare options (cog-like icon), Object Types pane, set the options as below. You might want to tweak those and select only the object types you want. Then, run the comparison, review and select your changes and apply them to the project.

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RSS feeds in Orchard

- by Bertrand Le Roy

When we added RSS to Orchard, we wanted to make it easy for any module to expose any contents as a feed. We also wanted the rendering of the feed to be handled by Orchard in order to minimize the amount of work from the module developer. A typical example of such feed exposition is of course blog feeds. We have an IFeedManager interface for which you can get the built-in implementation through dependency injection. Look at the BlogController constructor for an example: public BlogController( IOrchardServices services, IBlogService blogService, IBlogSlugConstraint blogSlugConstraint, IFeedManager feedManager, RouteCollection routeCollection) { If you look a little further in that same controller, in the Item action, you’ll see a call to the Register method of the feed manager: _feedManager.Register(blog); This in reality is a call into an extension method that is specialized for blogs, but we could have made the two calls to the actual generic Register directly in the action instead, that is just an implementation detail: feedManager.Register(blog.Name, "rss", new RouteValueDictionary { { "containerid", blog.Id } }); feedManager.Register(blog.Name + " - Comments", "rss", new RouteValueDictionary { { "commentedoncontainer", blog.Id } }); What those two effective calls are doing is to register two feeds: one for the blog itself and one for the comments on the blog. For each call, the name of the feed is provided, then we have the type of feed (“rss”) and some values to be injected into the generic RSS route that will be used later to route the feed to the right providers. This is all you have to do to expose a new feed. If you’re only interested in exposing feeds, you can stop right there. If on the other hand you want to know what happens after that under the hood, carry on. What happens after that is that the feedmanager will take care of formatting the link tag for the feed (see FeedManager.GetRegisteredLinks). The GetRegisteredLinks method itself will be called from a specialized filter, FeedFilter. FeedFilter is an MVC filter and the event we’re interested in hooking into is OnResultExecuting, which happens after the controller action has returned an ActionResult and just before MVC executes that action result. In other words, our feed registration has already been called but the view is not yet rendered. Here’s the code for OnResultExecuting: model.Zones.AddAction("head:after", html => html.ViewContext.Writer.Write( _feedManager.GetRegisteredLinks(html))); This is another piece of code whose execution is differed. It is saying that whenever comes time to render the “head” zone, this code should be called right after. The code itself is rendering the link tags. As a result of all that, here’s what can be found in an Orchard blog’s head section: <link rel="alternate" type="application/rss+xml" title="Tales from the Evil Empire" href="/rss?containerid=5" /> <link rel="alternate" type="application/rss+xml" title="Tales from the Evil Empire - Comments" href="/rss?commentedoncontainer=5" /> The generic action that these two feeds point to is Index on FeedController. That controller has three important dependencies: an IFeedBuilderProvider, an IFeedQueryProvider and an IFeedItemProvider. Different implementations of these interfaces can provide different formats of feeds, such as RSS and Atom. The Match method enables each of the competing providers to provide a priority for themselves based on arbitrary criteria that can be found on the FeedContext. This means that a provider can be selected based not only on the desired format, but also on the nature of the objects being exposed as a feed or on something even more arbitrary such as the destination device (you could imagine for example giving shorter text only excerpts of posts on mobile devices, and full HTML on desktop). The key here is extensibility and dynamic competition and collaboration from unknown and loosely coupled parts. You’ll find this pattern pretty much everywhere in the Orchard architecture. The RssFeedBuilder implementation of IFeedBuilderProvider is also a regular controller with a Process action that builds a RssResult, which is itself a thin ActionResult wrapper around an XDocument. Let’s get back to the FeedController’s Index action. After having called into each known feed builder to get its priority on the currently requested feed, it will select the one with the highest priority. The next thing it needs to do is to actually fetch the data for the feed. This again is a collaborative effort from a priori unknown providers, the implementations of IFeedQueryProvider. There are several implementations by default in Orchard, the choice of which is again done through a Match method. ContainerFeedQuery for example chimes in when a “containerid” parameter is found in the context (see URL in the link tag above): public FeedQueryMatch Match(FeedContext context) { var containerIdValue = context.ValueProvider.GetValue("containerid"); if (containerIdValue == null) return null; return new FeedQueryMatch { FeedQuery = this, Priority = -5 }; } The actual work is done in the Execute method, which finds the right container content item in the Orchard database and adds elements for each of them. In other words, the feed query provider knows how to retrieve the list of content items to add to the feed. The last step is to translate each of the content items into feed entries, which is done by implementations of IFeedItemBuilder. There is no Match method this time. Instead, all providers are called with the collection of items (or more accurately with the FeedContext, but this contains the list of items, which is what’s relevant in most cases). Each provider can then choose to pick those items that it knows how to treat and transform them into the format requested. This enables the construction of heterogeneous feeds that expose content items of various types into a single feed. That will be extremely important when you’ll want to expose a single feed for all your site. So here are feeds in Orchard in a nutshell. The main point here is that there is a fair number of components involved, with some complexity in implementation in order to allow for extreme flexibility, but the part that you use to expose a new feed is extremely simple and light: declare that you want your content exposed as a feed and you’re done. There are cases where you’ll have to dive in and provide new implementations for some or all of the interfaces involved, but that requirement will only arise as needed. For example, you might need to create a new feed item builder to include your custom content type but that effort will be extremely focused on the specialized task at hand. The rest of the system won’t need to change. So what do you think?

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JPA - insert and retrieve clob and blob types

- by pachunoori.vinay.kumar(at)oracle.com

This article describes about the JPA feature for handling clob and blob data types.You will learn the following in this article. @Lob annotation Client code to insert and retrieve the clob/blob types End to End ADFaces application to retrieve the image from database table and display it in web page. Use Case Description Persisting and reading the image from database using JPA clob/blob type. @Lob annotation By default, TopLink JPA assumes that all persistent data can be represented as typical database data types. Use the @Lob annotation with a basic mapping to specify that a persistent property or field should be persisted as a large object to a database-supported large object type. A Lob may be either a binary or character type. TopLink JPA infers the Lob type from the type of the persistent field or property. For string and character-based types, the default is Clob. In all other cases, the default is Blob. Example Below code shows how to use this annotation to specify that persistent field picture should be persisted as a Blob. public class Person implements Serializable { @Id @Column(nullable = false, length = 20) private String name; @Column(nullable = false) @Lob private byte[] picture; @Column(nullable = false, length = 20) } Client code to insert and retrieve the clob/blob types Reading a image file and inserting to Database table Below client code will read the image from a file and persist to Person table in database. Person p=new Person(); p.setName("Tom"); p.setSex("male"); p.setPicture(writtingImage("Image location"));// - c:\images\test.jpg sessionEJB.persistPerson(p); //Retrieving the image from Database table and writing to a file List<Person> plist=sessionEJB.getPersonFindAll();// Person person=(Person)plist.get(0);//get a person object retrieveImage(person.getPicture()); //get picture retrieved from Table //Private method to create byte[] from image file private static byte[] writtingImage(String fileLocation) { System.out.println("file lication is"+fileLocation); IOManager manager=new IOManager(); try { return manager.getBytesFromFile(fileLocation); } catch (IOException e) { } return null; } //Private method to read byte[] from database and write to a image file private static void retrieveImage(byte[] b) { IOManager manager=new IOManager(); try { manager.putBytesInFile("c:\\webtest.jpg",b); } catch (IOException e) { } } End to End ADFaces application to retrieve the image from database table and display it in web page. Please find the application in this link. Following are the j2ee components used in the sample application. ADFFaces(jspx page) HttpServlet Class - Will make a call to EJB and retrieve the person object from person table.Read the byte[] and write to response using Outputstream. SessionEJBBean - This is a session facade to make a local call to JPA entities JPA Entity(Person.java) - Person java class with setter and getter method annotated with @Lob representing the clob/blob types for picture field.

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Restful Services, oData, and Rest Sharp

- by jkrebsbach

After a great presentation by Jason Sheehan at MDC about RestSharp, I decided to implement it. RestSharp is a .Net framework for consuming restful data sources via either Json or XML. My first step was to put together a Restful data source for RestSharp to consume. Staying entirely withing .Net, I decided to use Microsoft's oData implementation, built on System.Data.Services.DataServices. Natively, these support Json, or atom+pub xml. (XML with a few bells and whistles added on) There are three main steps for creating an oData data source: 1) override CreateDSPMetaData This is where the metadata data is returned. The meta data defines the structure of the data to return. The structure contains the relationships between data objects, along with what properties the objects expose. The meta data can and should be somehow cached so that the structure is not rebuild with every data request. 2) override CreateDataSource The context contains the data the data source will publish. This method is the conduit which will populate the metadata objects to be returned to the requestor. 3) implement static InitializeService At this point we can set up security, along with setting up properties of the web service (versioning, etc) Here is a web service which publishes stock prices for various Products (stocks) in various Categories. namespace RestService { public class RestServiceImpl : DSPDataService<DSPContext> { private static DSPContext _context; private static DSPMetadata _metadata; /// <summary> /// Populate traversable data source /// </summary> /// <returns></returns> protected override DSPContext CreateDataSource() { if (_context == null) { _context = new DSPContext(); Category utilities = new Category(0); utilities.Name = "Electric"; Category financials = new Category(1); financials.Name = "Financial"; IList products = _context.GetResourceSetEntities("Products"); Product electric = new Product(0, utilities); electric.Name = "ABC Electric"; electric.Description = "Electric Utility"; electric.Price = 3.5; products.Add(electric); Product water = new Product(1, utilities); water.Name = "XYZ Water"; water.Description = "Water Utility"; water.Price = 2.4; products.Add(water); Product banks = new Product(2, financials); banks.Name = "FatCat Bank"; banks.Description = "A bank that's almost too big"; banks.Price = 19.9; // This will never get to the client products.Add(banks); IList categories = _context.GetResourceSetEntities("Categories"); categories.Add(utilities); categories.Add(financials); utilities.Products.Add(electric); utilities.Products.Add(electric); financials.Products.Add(banks); } return _context; } /// <summary> /// Setup rules describing published data structure - relationships between data, /// key field, other searchable fields, etc. /// </summary> /// <returns></returns> protected override DSPMetadata CreateDSPMetadata() { if (_metadata == null) { _metadata = new DSPMetadata("DemoService", "DataServiceProviderDemo"); // Define entity type product ResourceType product = _metadata.AddEntityType(typeof(Product), "Product"); _metadata.AddKeyProperty(product, "ProductID"); // Only add properties we wish to share with end users _metadata.AddPrimitiveProperty(product, "Name"); _metadata.AddPrimitiveProperty(product, "Description"); EntityPropertyMappingAttribute att = new EntityPropertyMappingAttribute("Name", SyndicationItemProperty.Title, SyndicationTextContentKind.Plaintext, true); product.AddEntityPropertyMappingAttribute(att); att = new EntityPropertyMappingAttribute("Description", SyndicationItemProperty.Summary, SyndicationTextContentKind.Plaintext, true); product.AddEntityPropertyMappingAttribute(att); // Define products as a set of product entities ResourceSet products = _metadata.AddResourceSet("Products", product); // Define entity type category ResourceType category = _metadata.AddEntityType(typeof(Category), "Category"); _metadata.AddKeyProperty(category, "CategoryID"); _metadata.AddPrimitiveProperty(category, "Name"); _metadata.AddPrimitiveProperty(category, "Description"); // Define categories as a set of category entities ResourceSet categories = _metadata.AddResourceSet("Categories", category); att = new EntityPropertyMappingAttribute("Name", SyndicationItemProperty.Title, SyndicationTextContentKind.Plaintext, true); category.AddEntityPropertyMappingAttribute(att); att = new EntityPropertyMappingAttribute("Description", SyndicationItemProperty.Summary, SyndicationTextContentKind.Plaintext, true); category.AddEntityPropertyMappingAttribute(att); // A product has a category, a category has products _metadata.AddResourceReferenceProperty(product, "Category", categories); _metadata.AddResourceSetReferenceProperty(category, "Products", products); } return _metadata; } /// <summary> /// Based on the requesting user, can set up permissions to Read, Write, etc. /// </summary> /// <param name="config"></param> public static void InitializeService(DataServiceConfiguration config) { config.SetEntitySetAccessRule("*", EntitySetRights.All); config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V2; config.DataServiceBehavior.AcceptProjectionRequests = true; } } } The objects prefixed with DSP come from the samples on the oData site: http://www.odata.org/developers The products and categories objects are POCO business objects with no special modifiers. Three main options are available for defining the MetaData of data sources in .Net: 1) Generate Entity Data model (Potentially directly from SQL Server database). This requires the least amount of manual interaction, and uses the edmx WYSIWYG editor to generate a data model. This can be directly tied to the SQL Server database and generated from the database if you want a data access layer tightly coupled with your database. 2) Object model decorations. If you already have a POCO data layer, you can decorate your objects with properties to statically inform the compiler how the objects are related. The disadvantage is there are now tags strewn about your business layer that need to be updated as the business rules change. 3) Programmatically construct metadata object. This is the object illustrated above in CreateDSPMetaData. This puts all relationship information into one central programmatic location. Here business rules are constructed when the DSPMetaData response object is returned. Once you have your service up and running, RestSharp is designed for XML / Json, along with the native Microsoft library. There are currently some differences between how Jason made RestSharp expect XML with how atom+pub works, so I found better results currently with the Json implementation - modifying the RestSharp XML parser to make an atom+pub parser is fairly trivial though, so use what implementation works best for you. I put together a sample console app which calls the RestSvcImpl.svc service defined above (and assumes it to be running on port 2000). I used both RestSharp as a client, and also the default Microsoft oData client tools. namespace RestConsole { class Program { private static DataServiceContext _ctx; private enum DemoType { Xml, Json } static void Main(string[] args) { // Microsoft implementation _ctx = new DataServiceContext(new System.Uri("http://localhost:2000/RestServiceImpl.svc")); var msProducts = RunQuery<Product>("Products").ToList(); var msCategory = RunQuery<Category>("/Products(0)/Category").AsEnumerable().Single(); var msFilteredProducts = RunQuery<Product>("/Products?$filter=length(Name) ge 4").ToList(); // RestSharp implementation DemoType demoType = DemoType.Json; var client = new RestClient("http://localhost:2000/RestServiceImpl.svc"); client.ClearHandlers(); // Remove all available handlers // Set up handler depending on what situation dictates if (demoType == DemoType.Json) client.AddHandler("application/json", new RestSharp.Deserializers.JsonDeserializer()); else if (demoType == DemoType.Xml) { client.AddHandler("application/atom+xml", new RestSharp.Deserializers.XmlDeserializer()); } var request = new RestRequest(); if (demoType == DemoType.Json) request.RootElement = "d"; // service root element for json else if (demoType == DemoType.Xml) { request.XmlNamespace = "http://www.w3.org/2005/Atom"; } // Return all products request.Resource = "/Products?$orderby=Name"; RestResponse<List<Product>> productsResp = client.Execute<List<Product>>(request); List<Product> products = productsResp.Data; // Find category for product with ProductID = 1 request.Resource = string.Format("/Products(1)/Category"); RestResponse<Category> categoryResp = client.Execute<Category>(request); Category category = categoryResp.Data; // Specialized queries request.Resource = string.Format("/Products?$filter=ProductID eq {0}", 1); RestResponse<Product> productResp = client.Execute<Product>(request); Product product = productResp.Data; request.Resource = string.Format("/Products?$filter=Name eq '{0}'", "XYZ Water"); productResp = client.Execute<Product>(request); product = productResp.Data; } private static IEnumerable<TElement> RunQuery<TElement>(string queryUri) { try { return _ctx.Execute<TElement>(new Uri(queryUri, UriKind.Relative)); } catch (Exception ex) { throw ex; } } } } Feel free to step through the code a few times and to attach a debugger to the service as well to see how and where the context and metadata objects are constructed and returned. Pay special attention to the response object being returned by the oData service - There are several properties of the RestRequest that can be used to help troubleshoot when the structure of the response is not exactly what would be expected.

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Getting a Web Resource Url in non WebForms Applications

- by Rick Strahl

WebResources in ASP.NET are pretty useful feature. WebResources are resources that are embedded into a .NET assembly and can be loaded from the assembly via a special resource URL. WebForms includes a method on the ClientScriptManager (Page.ClientScript) and the ScriptManager object to retrieve URLs to these resources. For example you can do: ClientScript.GetWebResourceUrl(typeof(ControlResources), ControlResources.JQUERY_SCRIPT_RESOURCE); GetWebResourceUrl requires a type (which is used for the assembly lookup in which to find the resource) and the resource id to lookup. GetWebResourceUrl() then returns a nasty old long URL like this: WebResource.axd?d=-b6oWzgbpGb8uTaHDrCMv59VSmGhilZP5_T_B8anpGx7X-PmW_1eu1KoHDvox-XHqA1EEb-Tl2YAP3bBeebGN65tv-7-yAimtG4ZnoWH633pExpJor8Qp1aKbk-KQWSoNfRC7rQJHXVP4tC0reYzVw2&t=634533278261362212 While lately excessive resource usage has been frowned upon especially by MVC developers who tend to opt for content distributed as files, I still think that Web Resources have their place even in non-WebForms applications. Also if you have existing assemblies that include resources like scripts and common image links it sure would be nice to access them from non-WebForms pages like MVC views or even in plain old Razor Web Pages. Where's my Page object Dude? Unfortunately natively ASP.NET doesn't have a mechanism for retrieving WebResource Urls outside of the WebForms engine. It's a feature that's specifically baked into WebForms and that relies specifically on the Page HttpHandler implementation. Both Page.ClientScript (obviously) and ScriptManager rely on a hosting Page object in order to work and the various methods off these objects require control instances passed. The reason for this is that the script managers can inject scripts and links into Page content (think RegisterXXXX methods) and for that a Page instance is required. However, for many other methods - like GetWebResourceUrl() - that simply return resources or resource links the Page reference is really irrelevant. While there's a separate ClientScriptManager class, it's marked as sealed and doesn't have any public constructors so you can't create your own instance (without Reflection). Even if it did the internal constructor it does have requires a Page reference. No good… So, can we get access to a WebResourceUrl generically without running in a WebForms Page instance? We just have to create a Page instance ourselves and use it internally. There's nothing intrinsic about the use of the Page class in ClientScript, at least for retrieving resources and resource Urls so it's easy to create an instance of a Page for example in a static method. For our needs of retrieving ResourceUrls or even actually retrieving script resources we can use a canned, non-configured Page instance we create on our own. The following works just fine: public static string GetWebResourceUrl(Type type, string resource ) { Page page = new Page(); return page.ClientScript.GetWebResourceUrl(type, resource); } A slight optimization for this might be to cache the created Page instance. Page tends to be a pretty heavy object to create each time a URL is required so you might want to cache the instance: public class WebUtils { private static Page CachedPage { get { if (_CachedPage == null) _CachedPage = new Page(); return _CachedPage; } } private static Page _CachedPage; public static string GetWebResourceUrl(Type type, string resource) { return CachedPage.ClientScript.GetWebResourceUrl(type, resource); } } You can now use GetWebResourceUrl in a Razor page like this: <!DOCTYPE html> <html <head> <script src="@WebUtils.GetWebResourceUrl(typeof(ControlResources),ControlResources.JQUERY_SCRIPT_RESOURCE)"> </script> </head> <body> <div class="errordisplay"> <img src="@WebUtils.GetWebResourceUrl(typeof(ControlResources),ControlResources.WARNING_ICON_RESOURCE)" /> This is only a Test! </div> </body> </html> And voila - there you have WebResources served from a non-Page based application. WebResources may be a on the way out, but legacy apps have them embedded and for some situations, like fallback scripts and some common image resources I still like to use them. Being able to use them from non-WebForms applications should have been built into the core ASP.NETplatform IMHO, but seeing that it's not this workaround is easy enough to implement.© Rick Strahl, West Wind Technologies, 2005-2011Posted in ASP.NET MVC Tweet (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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C# ?? null coalescing operator

- by anirudha

the null coalescing operator is used for set the value when object is null. if object have some value that nothing change and still have their default value they have. string str = "i am string"; string message = str ?? "it is null"; the message have same value as str variable because str not null. if str is null that message have value “it is null”; as declared in statement. coalescing operator does not work on nullable operator such as int?

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Inserting and Deleting Sub Rows in GridView

- by Vincent Maverick Durano

A user in the forums (http://forums.asp.net) is asking how to insert sub rows in GridView and also add delete functionality for the inserted sub rows. In this post I'm going to demonstrate how to this in ASP.NET WebForms. The basic idea to achieve this is we just need to insert row data in the DataSource that is being used in GridView since the GridView rows will be generated based on the DataSource data. To make it more clear then let's build up a sample application. To start fire up Visual Studio and create a WebSite or Web Application project and then add a new WebForm. In the WebForm ASPX page add this GridView markup below: 1: <asp:gridview ID="GridView1" runat="server" AutoGenerateColumns="false" onrowdatabound="GridView1_RowDataBound"> 2: <Columns> 3: <asp:BoundField DataField="RowNumber" HeaderText="Row Number" /> 4: <asp:TemplateField HeaderText="Header 1"> 5: <ItemTemplate> 6: <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox> 7: </ItemTemplate> 8: </asp:TemplateField> 9: <asp:TemplateField HeaderText="Header 2"> 10: <ItemTemplate> 11: <asp:TextBox ID="TextBox2" runat="server"></asp:TextBox> 12: </ItemTemplate> 13: </asp:TemplateField> 14: <asp:TemplateField HeaderText="Header 3"> 15: <ItemTemplate> 16: <asp:TextBox ID="TextBox3" runat="server"></asp:TextBox> 17: </ItemTemplate> 18: </asp:TemplateField> 19: <asp:TemplateField HeaderText="Action"> 20: <ItemTemplate> 21: <asp:LinkButton ID="LinkButton1" runat="server" onclick="LinkButton1_Click" Text="Insert"></asp:LinkButton> 22: </ItemTemplate> 23: </asp:TemplateField> 24: </Columns> 25: </asp:gridview> Then at the code behind source of ASPX page you can add this codes below: 1: private DataTable FillData() { 2: 3: DataTable dt = new DataTable(); 4: DataRow dr = null; 5: 6: //Create DataTable columns 7: dt.Columns.Add(new DataColumn("RowNumber", typeof(string))); 8: 9: //Create Row for each columns 10: dr = dt.NewRow(); 11: dr["RowNumber"] = 1; 12: dt.Rows.Add(dr); 13: 14: dr = dt.NewRow(); 15: dr["RowNumber"] = 2; 16: dt.Rows.Add(dr); 17: 18: dr = dt.NewRow(); 19: dr["RowNumber"] = 3; 20: dt.Rows.Add(dr); 21: 22: dr = dt.NewRow(); 23: dr["RowNumber"] = 4; 24: dt.Rows.Add(dr); 25: 26: dr = dt.NewRow(); 27: dr["RowNumber"] = 5; 28: dt.Rows.Add(dr); 29: 30: //Store the DataTable in ViewState for future reference 31: ViewState["CurrentTable"] = dt; 32: 33: return dt; 34: 35: } 36: 37: private void BindGridView(DataTable dtSource) { 38: GridView1.DataSource = dtSource; 39: GridView1.DataBind(); 40: } 41: 42: private DataRow InsertRow(DataTable dtSource, string value) { 43: DataRow dr = dtSource.NewRow(); 44: dr["RowNumber"] = value; 45: return dr; 46: } 47: //private DataRow DeleteRow(DataTable dtSource, 48: 49: protected void Page_Load(object sender, EventArgs e) { 50: if (!IsPostBack) { 51: BindGridView(FillData()); 52: } 53: } 54: 55: protected void LinkButton1_Click(object sender, EventArgs e) { 56: LinkButton lb = (LinkButton)sender; 57: GridViewRow row = (GridViewRow)lb.NamingContainer; 58: DataTable dtCurrentData = (DataTable)ViewState["CurrentTable"]; 59: if (lb.Text == "Insert") { 60: //Insert new row below the selected row 61: dtCurrentData.Rows.InsertAt(InsertRow(dtCurrentData, row.Cells[0].Text + "-sub"), row.RowIndex + 1); 62: 63: } 64: else { 65: //Delete selected sub row 66: dtCurrentData.Rows.RemoveAt(row.RowIndex); 67: } 68: 69: BindGridView(dtCurrentData); 70: ViewState["CurrentTable"] = dtCurrentData; 71: } 72: 73: protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e) { 74: if (e.Row.RowType == DataControlRowType.DataRow) { 75: if (e.Row.Cells[0].Text.Contains("-sub")) { 76: ((LinkButton)e.Row.FindControl("LinkButton1")).Text = "Delete"; 77: } 78: } 79: } As you can see the code above is pretty straight forward and self explainatory but just to give you a short explaination the code above is composed of three (3) private methods which are the FillData(), BindGridView and InsertRow(). The FillData() method is a method that returns a DataTable and basically creates a dummy data in the DataTable to be used as the GridView DataSource. You can replace the code in that method if you want to use actual data from database but for the purpose of this example I just fill the DataTable with a dummy data on it. The BindGridVew is a method that handles the actual binding of GridVew. The InsertRow() is a method that returns a DataRow. This method handles the insertion of the sub row. Now in the LinkButton OnClick event, we casted the sender to a LinkButton to determine the specific object that fires up the event and get the row values. We then reference the Data from ViewState to get the current data that is being used in the GridView. If the LinkButton text is "Insert" then we will insert new row to the DataSource ( in this case the DataTable) based on the rowIndex if not then Delete the sub row that was added. Here are some screen shots of the output below: On initial load: After inserting a sub row: That's it! I hope someone find this post useful! Technorati Tags: ASP.NET,C#,GridView

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SQL SERVER – Guest Post – Architecting Data Warehouse – Niraj Bhatt

- by pinaldave

Niraj Bhatt works as an Enterprise Architect for a Fortune 500 company and has an innate passion for building / studying software systems. He is a top rated speaker at various technical forums including Tech·Ed, MCT Summit, Developer Summit, and Virtual Tech Days, among others. Having run a successful startup for four years Niraj enjoys working on – IT innovations that can impact an enterprise bottom line, streamlining IT budgets through IT consolidation, architecture and integration of systems, performance tuning, and review of enterprise applications. He has received Microsoft MVP award for ASP.NET, Connected Systems and most recently on Windows Azure. When he is away from his laptop, you will find him taking deep dives in automobiles, pottery, rafting, photography, cooking and financial statements though not necessarily in that order. He is also a manager/speaker at BDOTNET, Asia’s largest .NET user group. Here is the guest post by Niraj Bhatt. As data in your applications grows it’s the database that usually becomes a bottleneck. It’s hard to scale a relational DB and the preferred approach for large scale applications is to create separate databases for writes and reads. These databases are referred as transactional database and reporting database. Though there are tools / techniques which can allow you to create snapshot of your transactional database for reporting purpose, sometimes they don’t quite fit the reporting requirements of an enterprise. These requirements typically are data analytics, effective schema (for an Information worker to self-service herself), historical data, better performance (flat data, no joins) etc. This is where a need for data warehouse or an OLAP system arises. A Key point to remember is a data warehouse is mostly a relational database. It’s built on top of same concepts like Tables, Rows, Columns, Primary keys, Foreign Keys, etc. Before we talk about how data warehouses are typically structured let’s understand key components that can create a data flow between OLTP systems and OLAP systems. There are 3 major areas to it: a) OLTP system should be capable of tracking its changes as all these changes should go back to data warehouse for historical recording. For e.g. if an OLTP transaction moves a customer from silver to gold category, OLTP system needs to ensure that this change is tracked and send to data warehouse for reporting purpose. A report in context could be how many customers divided by geographies moved from sliver to gold category. In data warehouse terminology this process is called Change Data Capture. There are quite a few systems that leverage database triggers to move these changes to corresponding tracking tables. There are also out of box features provided by some databases e.g. SQL Server 2008 offers Change Data Capture and Change Tracking for addressing such requirements. b) After we make the OLTP system capable of tracking its changes we need to provision a batch process that can run periodically and takes these changes from OLTP system and dump them into data warehouse. There are many tools out there that can help you fill this gap – SQL Server Integration Services happens to be one of them. c) So we have an OLTP system that knows how to track its changes, we have jobs that run periodically to move these changes to warehouse. The question though remains is how warehouse will record these changes? This structural change in data warehouse arena is often covered under something called Slowly Changing Dimension (SCD). While we will talk about dimensions in a while, SCD can be applied to pure relational tables too. SCD enables a database structure to capture historical data. This would create multiple records for a given entity in relational database and data warehouses prefer having their own primary key, often known as surrogate key. As I mentioned a data warehouse is just a relational database but industry often attributes a specific schema style to data warehouses. These styles are Star Schema or Snowflake Schema. The motivation behind these styles is to create a flat database structure (as opposed to normalized one), which is easy to understand / use, easy to query and easy to slice / dice. Star schema is a database structure made up of dimensions and facts. Facts are generally the numbers (sales, quantity, etc.) that you want to slice and dice. Fact tables have these numbers and have references (foreign keys) to set of tables that provide context around those facts. E.g. if you have recorded 10,000 USD as sales that number would go in a sales fact table and could have foreign keys attached to it that refers to the sales agent responsible for sale and to time table which contains the dates between which that sale was made. These agent and time tables are called dimensions which provide context to the numbers stored in fact tables. This schema structure of fact being at center surrounded by dimensions is called Star schema. A similar structure with difference of dimension tables being normalized is called a Snowflake schema. This relational structure of facts and dimensions serves as an input for another analysis structure called Cube. Though physically Cube is a special structure supported by commercial databases like SQL Server Analysis Services, logically it’s a multidimensional structure where dimensions define the sides of cube and facts define the content. Facts are often called as Measures inside a cube. Dimensions often tend to form a hierarchy. E.g. Product may be broken into categories and categories in turn to individual items. Category and Items are often referred as Levels and their constituents as Members with their overall structure called as Hierarchy. Measures are rolled up as per dimensional hierarchy. These rolled up measures are called Aggregates. Now this may seem like an overwhelming vocabulary to deal with but don’t worry it will sink in as you start working with Cubes and others. Let’s see few other terms that we would run into while talking about data warehouses. ODS or an Operational Data Store is a frequently misused term. There would be few users in your organization that want to report on most current data and can’t afford to miss a single transaction for their report. Then there is another set of users that typically don’t care how current the data is. Mostly senior level executives who are interesting in trending, mining, forecasting, strategizing, etc. don’t care for that one specific transaction. This is where an ODS can come in handy. ODS can use the same star schema and the OLAP cubes we saw earlier. The only difference is that the data inside an ODS would be short lived, i.e. for few months and ODS would sync with OLTP system every few minutes. Data warehouse can periodically sync with ODS either daily or weekly depending on business drivers. Data marts are another frequently talked about topic in data warehousing. They are subject-specific data warehouse. Data warehouses that try to span over an enterprise are normally too big to scope, build, manage, track, etc. Hence they are often scaled down to something called Data mart that supports a specific segment of business like sales, marketing, or support. Data marts too, are often designed using star schema model discussed earlier. Industry is divided when it comes to use of data marts. Some experts prefer having data marts along with a central data warehouse. Data warehouse here acts as information staging and distribution hub with spokes being data marts connected via data feeds serving summarized data. Others eliminate the need for a centralized data warehouse citing that most users want to report on detailed data. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Best Practices, Business Intelligence, Data Warehousing, Database, Pinal Dave, PostADay, Readers Contribution, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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ASP.NET MVC 3 Hosting :: ASP.NET MVC 3 First Look

- by mbridge

MVC 3 View Enhancements MVC 3 introduces two improvements to the MVC view engine: - Ability to select the view engine to use. MVC 3 allows you to select from any of your installed view engines from Visual Studio by selecting Add > View (including the newly introduced ASP.NET “Razor” engine”): - Support for the next ASP.NET “Razor” syntax. The newly previewed Razor syntax is a concise lightweight syntax. MVC 3 Control Enhancements - Global Filters: ASP.NET MVC 3 allows you to specify that a filter which applies globally to all Controllers within an app by adding it to the GlobalFilters collection. The RegisterGlobalFilters() method is now included in the default Global.asax class template and so provides a convenient place to do this since is will then be called by the Application_Start() method: void RegisterGlobalFilters(GlobalFilterCollection filters) { filters.Add(new HandleLoggingAttribute()); filters.Add(new HandleErrorAttribute()); } void Application_Start() { RegisterGlobalFilters (GlobalFilters.Filters); } - Dynamic ViewModel Property : MVC 3 augments the ViewData API with a new “ViewModel” property on Controller which is of type “dynamic” – and therefore enables you to use the new dynamic language support in C# and VB pass ViewData items using a cleaner syntax than the current dictionary API. Public ActionResult Index() { ViewModel.Message = "Hello World"; return View(); } - New ActionResult Types : MVC 3 includes three new ActionResult types and helper methods: 1. HttpNotFoundResult – indicates that a resource which was requested by the current URL was not found. HttpNotFoundResult will return a 404 HTTP status code to the calling client. 2. PermanentRedirects – The HttpRedirectResult class contains a new Boolean “Permanent” property which is used to indicate that a permanent redirect should be done. Permanent redirects use a HTTP 301 status code. The Controller class includes three new methods for performing these permanent redirects: RedirectPermanent(), RedirectToRoutePermanent(), andRedirectToActionPermanent(). All of these methods will return an instance of the HttpRedirectResult object with the Permanent property set to true. 3. HttpStatusCodeResult – used for setting an explicit response status code and its associated description. MVC 3 AJAX and JavaScript Enhancements MVC 3 ships with built-in JSON binding support which enables action methods to receive JSON-encoded data and then model-bind it to action method parameters. For example a jQuery client-side JavaScript could define a “save” event handler which will be invoked when the save button is clicked on the client. The code in the event handler then constructs a client-side JavaScript “product” object with 3 fields with their values retrieved from HTML input elements. Finally, it uses jQuery’s .ajax() method to POST a JSON based request which contains the product to a /theStore/UpdateProduct URL on the server: $('#save').click(function () { var product = { ProdName: $('#Name').val() Price: $('#Price').val(), } $.ajax({ url: '/theStore/UpdateProduct', type: "POST"; data: JSON.stringify(widget), datatype: "json", contentType: "application/json; charset=utf-8", success: function () { $('#message').html('Saved').fadeIn(), }, error: function () { $('#message').html('Error').fadeIn(), } }); return false; }); MVC will allow you to implement the /theStore/UpdateProduct URL on the server by using an action method as below. The UpdateProduct() action method will accept a strongly-typed Product object for a parameter. MVC 3 can now automatically bind an incoming JSON post value to the .NET Product type on the server without having to write any custom binding. [HttpPost] public ActionResult UpdateProduct(Product product) { // save logic here return null } MVC 3 Model Validation Enhancements MVC 3 builds on the MVC 2 model validation improvements by adding support for several of the new validation features within the System.ComponentModel.DataAnnotations namespace in .NET 4.0: - Support for the new DataAnnotations metadata attributes like DisplayAttribute. - Support for the improvements made to the ValidationAttribute class which now supports a new IsValid overload that provides more info on the current validation context, like what object is being validated. - Support for the new IValidatableObject interface which enables you to perform model-level validation and also provide validation error messages which are specific to the state of the overall model. MVC 3 Dependency Injection Enhancements MVC 3 includes better support for applying Dependency Injection (DI) and also integrating with Dependency Injection/IOC containers. Currently MVC 3 Preview 1 has support for DI in the below places: - Controllers (registering & injecting controller factories and injecting controllers) - Views (registering & injecting view engines, also for injecting dependencies into view pages) - Action Filters (locating and injecting filters) And this is another important blog about Microsoft .NET and technology: - Windows 2008 Blog - SharePoint 2010 Blog - .NET 4 Blog And you can visit here if you're looking for ASP.NET MVC 3 hosting

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CodePlex Daily Summary for Sunday, May 02, 2010

CodePlex Daily Summary for Sunday, May 02, 2010New ProjectsAdventureWorks in Access: AdventureWorks database in Access format. Data has been ported in Access starting from Adventure Works database for SQL Server 2008.amplifi: This project is still under construction. We will add more information here as soon as it is available.ASP.NET MVC Bug Tracker: Bug Track written in C# ASP.NET MVC 2BigDecimal: BigDecimal is an attempt to create a number class that can have large precision. It is developed in vb.net (.net 4).CBM-Command: Coming soon....Chuyou: ChuyouCMinus: A C Minus Compiler!Complex and advanced mathematical functions: Mathematics toolkit is a Class Library Project which help Programmers to Calculate Mathematics Functions easily.Confuser: Confuser is a obfuscator for .NET. It is developed in C# and using Mono.Cecil for assembly manipulation.easypos: Micro punto de venta que permite ventas express de ropa, que se acopla fácil y transaparente con el ERP Click OneElmech Address Book: Web based Address Book for maintaining details of your business clients. This project targets Suppliers - Traders - Manufacturers - users. Applicat...Feed Viewer: Feed Viewer is able to synchronize subscribed feed and red news among all computers you are using. It understands both RSS and Atom format. It can ...Google URL Shortener, C#: Implementation in C# of generating short URLs by Goo.gl service (Google URL Shortener)MARS - Medical Assistant Record System: MARS - Medical Assistant Record SystemRx Contrib: Rx Contrib is a library which contain extensions for the Rx frameworkSimple Service Administration Tool: A simple tool to start/stop/restart a service of a WinNT based system. The tool is placed in the task bar as a notify icon, so the specified servic...Vis3D: Visual 3D controls for Silverlight.VisContent: XML content controls for ASP.NET.Windows Phone 7 database: This project implements a Isolated Storage (IsolatedStorage) based database for Windows Phone 7. The database consists of table object, each one s...New Releases$log$ / Keyword Substitution / Expansion Check-In Policy (TFS - LogSubstPol): LogSubstPol_v1.2010.0.4 (VS2010): LogSubstPol is a TFS check-in policy which insertes the check-in comments and other keywords into your source code, so you can keep track of the ch...Bojinx: Bojinx Core V4.5.1: The following new features were added: You can now use either BojinxMXMLContext or ContextModule to configure your application or module context. ...CBM-Command: Initial Public Demonstration: Initial public demonstration version. Can browse attached drives and display directory of any attached drive. A common question is "How does it w...Confuser: Confuser v1.0: It is the Confuser v1.0 that used to confuse the reverse-engineers :)Font Family Name Retrieval: 2nd Release: Added New MKV Font Extractor application to showcase the library. MKV Font Extractor depends on MKVToolnix to be installed before it will work. R...Google URL Shortener, C#: Goo.gl-CS v1 Beta: Extract the ZIP file to any location. Two files have to be in the same folder!HouseFly controls: HouseFly controls alpha 0.9.6.1: HouseFly controls release 0.9.6.1 alphaIsWiX: IsWiX 1.0.261.0: Build 1.0.261.0 - built against Fireworks 1.0.264.0. Adds support for VS2010 Integration to support WiX 3.5 beta releases.Managed Extensibility Framework (MEF) Contrib: MefContrib 0.9.2.0: Added conventions based catalog (read more at http://www.thecodejunkie.com/2010/03/bringing-convention-based-registration.html) MEF + Unity integ...MARS - Medical Assistant Record System: license: licenseNSIS Autorun: NSIS Autorun 0.1.5: This release includes source code, executable binary, files and example materials.PHP.net: Release 0.0.0.1: This is the first release of PHP.Net. The features available in this release are: new File Save File Save As Open File In the rar file is th...Rx Contrib: V1: Rx Contrib is ongoing effort for community additions for Rx. Current features are: ReactiveQueue: ISubject that does not loose values if there are ...Silverlight 4.0 Popup Menu: Context Menu for Silverlight 4 v1.0: - Added a margin for icon display. - Added the PopupMenuItem class which is a derivative of the DockPanel. - Find* methods can now drill down the v...Silverlight 4.0 Popup Menu: Context Menu for Silverlight 4 v1.1 Beta: - Added a margin for icon display. - Added the PopupMenuItem class which is a derivative of the DockPanel. - Added a AddSeperator method. - The Fin...Simple Service Administration Tool: SSATool 0.1.3: New Simple Service Administration Tool Version 0.1.3 compiled with Visual Studio .NET 2010.sMAPedit: sMAPedit v0.7a + Map-Pack: Required Additional Map-Pack Added: height setting by color picker (shift+leftclick)sMAPedit: sMAPedit v0.7b: Fixed: force a gargabe collection update to prevent pictureBox's memory leaksqwarea: Sqwarea 0.0.228.0 (alpha): This release corrects a critical bug in ConnexityNotifier service. We strongly recommend you to upgrade to this version. Known bugs : if you open...StackOverflow Desktop Client in C# and WPF: StackOverflow Client 0.1: Source code for the sample.TortoiseHg: TortoiseHg 1.0.2: This is a bug fix release, we recommend all users upgrade to 1.0.2VCC: Latest build, v2.1.30501.0: Automatic drop of latest buildVidCoder: 0.4.0: Changes: Added ability to queue up multiple video files or titles at once. These queued jobs will use the currently selected encoding settings. Mul...WabbitStudio Z80 Software Tools: Wabbitemu 32-bit Test Release: Wabbitemu Visual Studio build for testing purposesWindows Phone 7 database: Initial Release v1.0: This project implements a Isolated Storage (IsolatedStorage) based database for Windows Phone 7. The usage of this software is very simple. You cre...YouTubeEmbeddedVideo WebControl for ASP.NET: VideoControls version 1: This zip file contains the VideoControls.dll, version 1.Most Popular ProjectsRawrWBFS ManagerAJAX Control Toolkitpatterns & practices – Enterprise LibraryMicrosoft SQL Server Product Samples: DatabaseSilverlight ToolkitWindows Presentation Foundation (WPF)iTuner - The iTunes CompanionASP.NETDotNetNuke® Community EditionMost Active Projectspatterns & practices – Enterprise LibraryRawrIonics Isapi Rewrite FilterHydroServer - CUAHSI Hydrologic Information System Serverpatterns & practices: Azure Security GuidanceTinyProjectNB_Store - Free DotNetNuke Ecommerce Catalog ModuleBlogEngine.NETDambach Linear Algebra FrameworkFacebook Developer Toolkit

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Global Cache CR Requested But Current Block Received

- by Liu Maclean(???)

????????«MINSCN?Cache Fusion Read Consistent» ????,???????????? ??????????????????: SQL> select * from V$version; BANNER -------------------------------------------------------------------------------- Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production PL/SQL Release 11.2.0.3.0 - Production CORE 11.2.0.3.0 Production TNS for Linux: Version 11.2.0.3.0 - Production NLSRTL Version 11.2.0.3.0 - Production SQL> select count(*) from gv$instance; COUNT(*) ---------- 2 SQL> select * from global_name; GLOBAL_NAME -------------------------------------------------------------------------------- www.oracledatabase12g.com ?11gR2 2??RAC??????????status???XG,????Xcurrent block???INSTANCE 2?hold?,?????INSTANCE 1?????????,?????: SQL> select * from test; ID ---------- 1 2 SQL> select dbms_rowid.rowid_block_number(rowid),dbms_rowid.rowid_relative_fno(rowid) from test; DBMS_ROWID.ROWID_BLOCK_NUMBER(ROWID) DBMS_ROWID.ROWID_RELATIVE_FNO(ROWID) ------------------------------------ ------------------------------------ 89233 1 89233 1 SQL> alter system flush buffer_cache; System altered. INSTANCE 1 Session A: SQL> update test set id=id+1 where id=1; 1 row updated. INSTANCE 1 Session B: SQL> select state,cr_scn_bas from x$bh where file#=1 and dbablk=89233 and state!=0; STATE CR_SCN_BAS ---------- ---------- 1 0 3 1755287 SQL> oradebug setmypid; Statement processed. SQL> oradebug dump gc_elements 255; Statement processed. SQL> oradebug tracefile_name; /s01/orabase/diag/rdbms/vprod/VPROD1/trace/VPROD1_ora_19111.trc GLOBAL CACHE ELEMENT DUMP (address: 0xa4ff3080): id1: 0x15c91 id2: 0x1 pkey: OBJ#76896 block: (1/89233) lock: X rls: 0x0 acq: 0x0 latch: 3 flags: 0x20 fair: 0 recovery: 0 fpin: 'kdswh11: kdst_fetch' bscn: 0x0.146e20 bctx: (nil) write: 0 scan: 0x0 lcp: (nil) lnk: [NULL] lch: [0xa9f6a6f8,0xa9f6a6f8] seq: 32 hist: 58 145:0 118 66 144:0 192 352 197 48 121 113 424 180 58 LIST OF BUFFERS LINKED TO THIS GLOBAL CACHE ELEMENT: flg: 0x02000001 lflg: 0x1 state: XCURRENT tsn: 0 tsh: 2 addr: 0xa9f6a5c8 obj: 76896 cls: DATA bscn: 0x0.1ac898 BH (0xa9f6a5c8) file#: 1 rdba: 0x00415c91 (1/89233) class: 1 ba: 0xa9e56000 set: 5 pool: 3 bsz: 8192 bsi: 0 sflg: 3 pwc: 0,15 dbwrid: 0 obj: 76896 objn: 76896 tsn: 0 afn: 1 hint: f hash: [0x91f4e970,0xbae9d5b8] lru: [0x91f58848,0xa9f6a828] lru-flags: debug_dump obj-flags: object_ckpt_list ckptq: [0x9df6d1d8,0xa9f6a740] fileq: [0xa2ece670,0xbdf4ed68] objq: [0xb4964e00,0xb4964e00] objaq: [0xb4964de0,0xb4964de0] st: XCURRENT md: NULL fpin: 'kdswh11: kdst_fetch' tch: 2 le: 0xa4ff3080 flags: buffer_dirty redo_since_read LRBA: [0x19.5671.0] LSCN: [0x0.1ac898] HSCN: [0x0.1ac898] HSUB: [1] buffer tsn: 0 rdba: 0x00415c91 (1/89233) scn: 0x0000.001ac898 seq: 0x01 flg: 0x00 tail: 0xc8980601 frmt: 0x02 chkval: 0x0000 type: 0x06=trans data ??????block: (1/89233)?GLOBAL CACHE ELEMENT DUMP?LOCK????X ??XG , ??????Current Block????Instance??modify???,????????????? ????Instance 2 ????: Instance 2 Session C: SQL> update test set id=id+1 where id=2; 1 row updated. Instance 2 Session D: SQL> select state,cr_scn_bas from x$bh where file#=1 and dbablk=89233 and state!=0; STATE CR_SCN_BAS ---------- ---------- 1 0 3 1756658 SQL> oradebug setmypid; Statement processed. SQL> oradebug dump gc_elements 255; Statement processed. SQL> oradebug tracefile_name; /s01/orabase/diag/rdbms/vprod/VPROD2/trace/VPROD2_ora_13038.trc GLOBAL CACHE ELEMENT DUMP (address: 0x89fb25a0): id1: 0x15c91 id2: 0x1 pkey: OBJ#76896 block: (1/89233) lock: XG rls: 0x0 acq: 0x0 latch: 3 flags: 0x20 fair: 0 recovery: 0 fpin: 'kduwh01: kdusru' bscn: 0x0.1acdf3 bctx: (nil) write: 0 scan: 0x0 lcp: (nil) lnk: [NULL] lch: [0x96f4cf80,0x96f4cf80] seq: 61 hist: 324 21 143:0 19 16 352 329 144:6 14 7 352 197 LIST OF BUFFERS LINKED TO THIS GLOBAL CACHE ELEMENT: flg: 0x0a000001 state: XCURRENT tsn: 0 tsh: 1 addr: 0x96f4ce50 obj: 76896 cls: DATA bscn: 0x0.1acdf6 BH (0x96f4ce50) file#: 1 rdba: 0x00415c91 (1/89233) class: 1 ba: 0x96bd4000 set: 5 pool: 3 bsz: 8192 bsi: 0 sflg: 2 pwc: 0,15 dbwrid: 0 obj: 76896 objn: 76896 tsn: 0 afn: 1 hint: f hash: [0x96ee1fe8,0xbae9d5b8] lru: [0x96f4d0b0,0x96f4cdc0] obj-flags: object_ckpt_list ckptq: [0xbdf519b8,0x96f4d5a8] fileq: [0xbdf519d8,0xbdf519d8] objq: [0xb4a47b90,0xb4a47b90] objaq: [0x96f4d0e8,0xb4a47b70] st: XCURRENT md: NULL fpin: 'kduwh01: kdusru' tch: 1 le: 0x89fb25a0 flags: buffer_dirty redo_since_read remote_transfered LRBA: [0x11.9e18.0] LSCN: [0x0.1acdf6] HSCN: [0x0.1acdf6] HSUB: [1] buffer tsn: 0 rdba: 0x00415c91 (1/89233) scn: 0x0000.001acdf6 seq: 0x01 flg: 0x00 tail: 0xcdf60601 frmt: 0x02 chkval: 0x0000 type: 0x06=trans data GCS CLIENT 0x89fb2618,6 resp[(nil),0x15c91.1] pkey 76896.0 grant 2 cvt 0 mdrole 0x42 st 0x100 lst 0x20 GRANTQ rl G0 master 1 owner 2 sid 0 remote[(nil),0] hist 0x94121c601163423c history 0x3c.0x4.0xd.0xb.0x1.0xc.0x7.0x9.0x14.0x1. cflag 0x0 sender 1 flags 0x0 replay# 0 abast (nil).x0.1 dbmap (nil) disk: 0x0000.00000000 write request: 0x0000.00000000 pi scn: 0x0000.00000000 sq[(nil),(nil)] msgseq 0x1 updseq 0x0 reqids[6,0,0] infop (nil) lockseq x2b8 pkey 76896.0 hv 93 [stat 0x0, 1->1, wm 32768, RMno 0, reminc 18, dom 0] kjga st 0x4, step 0.0.0, cinc 20, rmno 6, flags 0x0 lb 0, hb 0, myb 15250, drmb 15250, apifrz 0 ?Instance 2??????block: (1/89233)? GLOBAL CACHE ELEMENT Lock Convert?lock: XG ????GC_ELEMENTS DUMP???XCUR Cache Fusion?,???????X$ VIEW,??? X$LE X$KJBR X$KJBL, ???X$ VIEW???????????????????: INSTANCE 2 Session D: SELECT * FROM x$le WHERE le_addr IN (SELECT le_addr FROM x$bh WHERE obj IN (SELECT data_object_id FROM dba_objects WHERE owner = 'SYS' AND object_name = 'TEST') AND class = 1 AND state != 3); ADDR INDX INST_ID LE_ADDR LE_ID1 LE_ID2 ---------------- ---------- ---------- ---------------- ---------- ---------- LE_RLS LE_ACQ LE_FLAGS LE_MODE LE_WRITE LE_LOCAL LE_RECOVERY ---------- ---------- ---------- ---------- ---------- ---------- ----------- LE_BLKS LE_TIME LE_KJBL ---------- ---------- ---------------- 00007F94CA14CF60 7003 2 0000000089FB25A0 89233 1 0 0 32 2 0 1 0 1 0 0000000089FB2618 PCM Resource NAME?[ID1][ID2],[BL]???, ID1?ID2 ??blockno? fileno????, ??????????GC_elements dump?? id1: 0x15c91 id2: 0×1 pkey: OBJ#76896 block: (1/89233)?? ,? kjblname ? kjbrname ??”[0x15c91][0x1],[BL]” ??: INSTANCE 2 Session D: SQL> set linesize 80 pagesize 1400 SQL> SELECT * 2 FROM x$kjbl l 3 WHERE l.kjblname LIKE '%[0x15c91][0x1],[BL]%'; ADDR INDX INST_ID KJBLLOCKP KJBLGRANT KJBLREQUE ---------------- ---------- ---------- ---------------- --------- --------- KJBLROLE KJBLRESP KJBLNAME ---------- ---------------- ------------------------------ KJBLNAME2 KJBLQUEUE ------------------------------ ---------- KJBLLOCKST KJBLWRITING ---------------------------------------------------------------- ----------- KJBLREQWRITE KJBLOWNER KJBLMASTER KJBLBLOCKED KJBLBLOCKER KJBLSID KJBLRDOMID ------------ ---------- ---------- ----------- ----------- ---------- ---------- KJBLPKEY ---------- 00007F94CA22A288 451 2 0000000089FB2618 KJUSEREX KJUSERNL 0 00 [0x15c91][0x1],[BL][ext 0x0,0x 89233,1,BL 0 GRANTED 0 0 1 0 0 0 0 0 76896 SQL> SELECT r.* FROM x$kjbr r WHERE r.kjbrname LIKE '%[0x15c91][0x1],[BL]%'; no rows selected Instance 1 session B: SQL> SELECT r.* FROM x$kjbr r WHERE r.kjbrname LIKE '%[0x15c91][0x1],[BL]%'; ADDR INDX INST_ID KJBRRESP KJBRGRANT KJBRNCVL ---------------- ---------- ---------- ---------------- --------- --------- KJBRROLE KJBRNAME KJBRMASTER KJBRGRANTQ ---------- ------------------------------ ---------- ---------------- KJBRCVTQ KJBRWRITER KJBRSID KJBRRDOMID KJBRPKEY ---------------- ---------------- ---------- ---------- ---------- 00007F801ACA68F8 1355 1 00000000B5A62AE0 KJUSEREX KJUSERNL 0 [0x15c91][0x1],[BL][ext 0x0,0x 0 00000000B48BB330 00 00 0 0 76896 ??????Instance 1???block: (1/89233),??????Instance 2 build cr block ????Instance 1, ?????????? ????? Instance 1? Foreground Process ? Instance 2?LMS??????RAC TRACE: Instance 2: [oracle@vrh2 ~]$ ps -ef|grep ora_lms|grep -v grep oracle 23364 1 0 Apr29 ? 00:33:15 ora_lms0_VPROD2 SQL> oradebug setospid 23364 Oracle pid: 13, Unix process pid: 23364, image: [email protected] (LMS0) SQL> oradebug event 10046 trace name context forever,level 8:10708 trace name context forever,level 103: trace[rac.*] disk high; Statement processed. SQL> oradebug tracefile_name /s01/orabase/diag/rdbms/vprod/VPROD2/trace/VPROD2_lms0_23364.trc Instance 1 session B : SQL> select state,cr_scn_bas from x$bh where file#=1 and dbablk=89233 and state!=0; STATE CR_SCN_BAS ---------- ---------- 3 1756658 3 1756661 3 1755287 Instance 1 session A : SQL> alter session set events '10046 trace name context forever,level 8:10708 trace name context forever,level 103: trace[rac.*] disk high'; Session altered. SQL> select * from test; ID ---------- 2 2 SQL> select state,cr_scn_bas from x$bh where file#=1 and dbablk=89233 and state!=0; STATE CR_SCN_BAS ---------- ---------- 3 1761520 ?x$BH?????,???????Instance 1???build??CR block,????? TRACE ??: Instance 1 foreground Process: PARSING IN CURSOR #140336527348792 len=18 dep=0 uid=0 oct=3 lid=0 tim=1335939136125254 hv=1689401402 ad='b1a4c828' sqlid='c99yw1xkb4f1u' select * from test END OF STMT PARSE #140336527348792:c=2999,e=2860,p=0,cr=0,cu=0,mis=1,r=0,dep=0,og=1,plh=1357081020,tim=1335939136125253 EXEC #140336527348792:c=0,e=40,p=0,cr=0,cu=0,mis=0,r=0,dep=0,og=1,plh=1357081020,tim=1335939136125373 WAIT #140336527348792: nam='SQL*Net message to client' ela= 6 driver id=1650815232 #bytes=1 p3=0 obj#=0 tim=1335939136125420 *** 2012-05-02 02:12:16.125 kclscrs: req=0 block=1/89233 2012-05-02 02:12:16.125574 : kjbcro[0x15c91.1 76896.0][4] *** 2012-05-02 02:12:16.125 kclscrs: req=0 typ=nowait-abort *** 2012-05-02 02:12:16.125 kclscrs: bid=1:3:1:0:f:1e:0:0:10:0:0:0:1:2:4:1:20:0:0:0:c3:49:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:4:3:2:1:2:0:1c:0:4d:26:a3:52:0:0:0:0:c7:c:ca:62:c3:49:0:0:0:0:1:0:14:8e:47:76:1:2:dc:5:a9:fe:17:75:0:0:0:0:0:0:0:0:0:0:0:0:99:ed:0:0:0:0:0:0:10:0:0:0 2012-05-02 02:12:16.125718 : kjbcro[0x15c91.1 76896.0][4] 2012-05-02 02:12:16.125751 : GSIPC:GMBQ: buff 0xba0ee018, queue 0xbb79a7b8, pool 0x60013fa0, freeq 0, nxt 0xbb79a7b8, prv 0xbb79a7b8 2012-05-02 02:12:16.125780 : kjbsentscn[0x0.1ae0f0][to 2] 2012-05-02 02:12:16.125806 : GSIPC:SENDM: send msg 0xba0ee088 dest x20001 seq 177740 type 36 tkts xff0000 mlen x1680198 2012-05-02 02:12:16.125918 : kjbmscr(0x15c91.1)reqid=0x8(req 0xa4ff30f8)(rinst 1)hldr 2(infosz 200)(lseq x2b8) 2012-05-02 02:12:16.126959 : GSIPC:KSXPCB: msg 0xba0ee088 status 30, type 36, dest 2, rcvr 1 *** 2012-05-02 02:12:16.127 kclwcrs: wait=0 tm=1233 *** 2012-05-02 02:12:16.127 kclwcrs: got 1 blocks from ksxprcv WAIT #140336527348792: nam='gc cr block 2-way' ela= 1233 p1=1 p2=89233 p3=1 obj#=76896 tim=1335939136127199 2012-05-02 02:12:16.127272 : kjbcrcomplete[0x15c91.1 76896.0][0] 2012-05-02 02:12:16.127309 : kjbrcvdscn[0x0.1ae0f0][from 2][idx 2012-05-02 02:12:16.127329 : kjbrcvdscn[no bscn <= rscn 0x0.1ae0f0][from 2] ???? kjbcro[0x15c91.1 76896.0][4] kjbsentscn[0x0.1ae0f0][to 2] ?Instance 2??SCN=1ae0f0=1761520? block: (1/89233),???’gc cr block 2-way’ ??,?????????CR block? Instance 2 LMS TRACE 2012-05-02 02:12:15.634057 : GSIPC:RCVD: ksxp msg 0x7f16e1598588 sndr 1 seq 0.177740 type 36 tkts 0 2012-05-02 02:12:15.634094 : GSIPC:RCVD: watq msg 0x7f16e1598588 sndr 1, seq 177740, type 36, tkts 0 2012-05-02 02:12:15.634108 : GSIPC:TKT: collect msg 0x7f16e1598588 from 1 for rcvr -1, tickets 0 2012-05-02 02:12:15.634162 : kjbrcvdscn[0x0.1ae0f0][from 1][idx 2012-05-02 02:12:15.634186 : kjbrcvdscn[no bscn1, wm 32768, RMno 0, reminc 18, dom 0] kjga st 0x4, step 0.0.0, cinc 20, rmno 6, flags 0x0 lb 0, hb 0, myb 15250, drmb 15250, apifrz 0 GCS CLIENT END 2012-05-02 02:12:15.635211 : kjbdowncvt[0x15c91.1 76896.0][1][options x0] 2012-05-02 02:12:15.635230 : GSIPC:AMBUF: rcv buff 0x7f16e1c56420, pool rcvbuf, rqlen 1103 2012-05-02 02:12:15.635308 : GSIPC:GPBMSG: new bmsg 0x7f16e1c56490 mb 0x7f16e1c56420 msg 0x7f16e1c564b0 mlen 152 dest x101 flushsz -1 2012-05-02 02:12:15.635334 : kjbmslset(0x15c91.1)) seq 0x4 reqid=0x6 (shadow 0xb48bb330.xb)(rsn 2)(mas@1) 2012-05-02 02:12:15.635355 : GSIPC:SPBMSG: send bmsg 0x7f16e1c56490 blen 184 msg 0x7f16e1c564b0 mtype 33 attr|dest x30101 bsz|fsz x1ffff 2012-05-02 02:12:15.635377 : GSIPC:SNDQ: enq msg 0x7f16e1c56490, type 65521 seq 118669, inst 1, receiver 1, queued 1 *** 2012-05-02 02:12:15.635 kclccctx: cleanup copy 0x7f16e1d94798 2012-05-02 02:12:15.635479 : [kjmpmsgi:compl][type 36][msg 0x7f16e1598588][seq 177740.0][qtime 0][ptime 1257] 2012-05-02 02:12:15.635511 : GSIPC:BSEND: flushing sndq 0xb491dd28, id 1, dcx 0xbc516778, inst 1, rcvr 1 qlen 0 1 2012-05-02 02:12:15.635536 : GSIPC:BSEND: no batch1 msg 0x7f16e1c56490 type 65521 len 184 dest (1:1) 2012-05-02 02:12:15.635557 : kjbsentscn[0x0.1ae0f1][to 1] 2012-05-02 02:12:15.635578 : GSIPC:SENDM: send msg 0x7f16e1c56490 dest x10001 seq 118669 type 65521 tkts x10002 mlen xb800e8 WAIT #0: nam='gcs remote message' ela= 180 waittime=1 poll=0 event=0 obj#=0 tim=1335939135635819 2012-05-02 02:12:15.635853 : GSIPC:RCVD: ksxp msg 0x7f16e167e0b0 sndr 1 seq 0.177741 type 32 tkts 0 2012-05-02 02:12:15.635875 : GSIPC:RCVD: watq msg 0x7f16e167e0b0 sndr 1, seq 177741, type 32, tkts 0 2012-05-02 02:12:15.636012 : GSIPC:TKT: collect msg 0x7f16e167e0b0 from 1 for rcvr -1, tickets 0 2012-05-02 02:12:15.636040 : kjbrcvdscn[0x0.1ae0f1][from 1][idx 2012-05-02 02:12:15.636060 : kjbrcvdscn[no bscn <= rscn 0x0.1ae0f1][from 1] 2012-05-02 02:12:15.636082 : GSIPC:TKT: dest (1:1) rtkt not acked 1 unassigned bufs 0 tkts 0 newbufs 0 2012-05-02 02:12:15.636102 : GSIPC:TKT: remove ctx dest (1:1) 2012-05-02 02:12:15.636125 : [kjmxmpm][type 32][seq 0.177741][msg 0x7f16e167e0b0][from 1] 2012-05-02 02:12:15.636146 : kjbmpocr(0xb0.6)seq 0x1,reqid=0x23a,(client 0x9fff7b58,0x1)(from 1)(lseq xdf0) 2????LMS????????? ??gcs remote message GSIPC ????SCN=[0x0.1ae0f0] block=1/89233???,??BAST kjbmpbast(0x15c91.1),?? block=1/89233??????? ??fairness??(?11.2.0.3???_fairness_threshold=2),?current block?KCL: F156: fairness downconvert,?Xcurrent DownConvert? Scurrent: Instance 2: SQL> select state,cr_scn_bas from x$bh where file#=1 and dbablk=89233 and state!=0; STATE CR_SCN_BAS ---------- ---------- 2 0 3 1756658 ??Instance 2 LMS ?cr block??? kjbmslset(0x15c91.1)) ????SEND QUEUE GSIPC:SNDQ: enq msg 0x7f16e1c56490? ???????Instance 1???? block: (1/89233)??? ??????: Instance 2: SQL> select CURRENT_RESULTS,LIGHT_WORKS from v$cr_block_server; CURRENT_RESULTS LIGHT_WORKS --------------- ----------- 29273 437 Instance 1 session A: SQL> SQL> select * from test; ID ---------- 2 2 SQL> select state,cr_scn_bas from x$bh where file#=1 and dbablk=89233 and state!=0; STATE CR_SCN_BAS ---------- ---------- 3 1761942 3 1761932 1 0 3 1761520 Instance 2: SQL> select CURRENT_RESULTS,LIGHT_WORKS from v$cr_block_server; CURRENT_RESULTS LIGHT_WORKS --------------- ----------- 29274 437 select * from test END OF STMT PARSE #140336529675592:c=0,e=337,p=0,cr=0,cu=0,mis=0,r=0,dep=0,og=1,plh=1357081020,tim=1335939668940051 EXEC #140336529675592:c=0,e=96,p=0,cr=0,cu=0,mis=0,r=0,dep=0,og=1,plh=1357081020,tim=1335939668940204 WAIT #140336529675592: nam='SQL*Net message to client' ela= 5 driver id=1650815232 #bytes=1 p3=0 obj#=0 tim=1335939668940348 *** 2012-05-02 02:21:08.940 kclscrs: req=0 block=1/89233 2012-05-02 02:21:08.940676 : kjbcro[0x15c91.1 76896.0][5] *** 2012-05-02 02:21:08.940 kclscrs: req=0 typ=nowait-abort *** 2012-05-02 02:21:08.940 kclscrs: bid=1:3:1:0:f:21:0:0:10:0:0:0:1:2:4:1:20:0:0:0:c3:49:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:0:4:3:2:1:2:0:1f:0:4d:26:a3:52:0:0:0:0:c7:c:ca:62:c3:49:0:0:0:0:1:0:17:8e:47:76:1:2:dc:5:a9:fe:17:75:0:0:0:0:0:0:0:0:0:0:0:0:99:ed:0:0:0:0:0:0:10:0:0:0 2012-05-02 02:21:08.940799 : kjbcro[0x15c91.1 76896.0][5] 2012-05-02 02:21:08.940833 : GSIPC:GMBQ: buff 0xba0ee018, queue 0xbb79a7b8, pool 0x60013fa0, freeq 0, nxt 0xbb79a7b8, prv 0xbb79a7b8 2012-05-02 02:21:08.940859 : kjbsentscn[0x0.1ae28c][to 2] 2012-05-02 02:21:08.940870 : GSIPC:SENDM: send msg 0xba0ee088 dest x20001 seq 177810 type 36 tkts xff0000 mlen x1680198 2012-05-02 02:21:08.940976 : kjbmscr(0x15c91.1)reqid=0xa(req 0xa4ff30f8)(rinst 1)hldr 2(infosz 200)(lseq x2b8) 2012-05-02 02:21:08.941314 : GSIPC:KSXPCB: msg 0xba0ee088 status 30, type 36, dest 2, rcvr 1 *** 2012-05-02 02:21:08.941 kclwcrs: wait=0 tm=707 *** 2012-05-02 02:21:08.941 kclwcrs: got 1 blocks from ksxprcv 2012-05-02 02:21:08.941818 : kjbassume[0x15c91.1][sender 2][mymode x1][myrole x0][srole x0][flgs x0][spiscn 0x0.0][swscn 0x0.0] 2012-05-02 02:21:08.941852 : kjbrcvdscn[0x0.1ae28d][from 2][idx 2012-05-02 02:21:08.941871 : kjbrcvdscn[no bscn ??????????????SCN=[0x0.1ae28c]=1761932 Version?CR block, ????receive????Xcurrent Block??SCN=1ae28d=1761933,Instance 1???Xcurrent Block???build????????SCN=1761932?CR BLOCK, ????????Current block,?????????'gc current block 2-way'? ?????????????request current block,?????kjbcro;?????Instance 2?LMS???????Current Block: Instance 2 LMS trace: 2012-05-02 02:21:08.448743 : GSIPC:RCVD: ksxp msg 0x7f16e14a4398 sndr 1 seq 0.177810 type 36 tkts 0 2012-05-02 02:21:08.448778 : GSIPC:RCVD: watq msg 0x7f16e14a4398 sndr 1, seq 177810, type 36, tkts 0 2012-05-02 02:21:08.448798 : GSIPC:TKT: collect msg 0x7f16e14a4398 from 1 for rcvr -1, tickets 0 2012-05-02 02:21:08.448816 : kjbrcvdscn[0x0.1ae28c][from 1][idx 2012-05-02 02:21:08.448834 : kjbrcvdscn[no bscn <= rscn 0x0.1ae28c][from 1] 2012-05-02 02:21:08.448857 : GSIPC:TKT: dest (1:1) rtkt not acked 2 unassigned bufs 0 tkts 0 newbufs 0 2012-05-02 02:21:08.448875 : GSIPC:TKT: remove ctx dest (1:1) 2012-05-02 02:21:08.448970 : [kjmxmpm][type 36][seq 0.177810][msg 0x7f16e14a4398][from 1] 2012-05-02 02:21:08.448993 : kjbmpbast(0x15c91.1) reqid=0x6 (req 0xa4ff30f8)(reqinst 1)(reqid 10)(flags x0) *** 2012-05-02 02:21:08.449 kclcrrf: req=48054 block=1/89233 *** 2012-05-02 02:21:08.449 kcl_compress_block: compressed: 6 free space: 7680 2012-05-02 02:21:08.449085 : kjbsentscn[0x0.1ae28d][to 1] 2012-05-02 02:21:08.449142 : kjbdeliver[to 1][0xa4ff30f8][10][current 1] 2012-05-02 02:21:08.449164 : kjbmssch(reqlock 0xa4ff30f8,10)(to 1)(bsz 344) 2012-05-02 02:21:08.449183 : GSIPC:AMBUF: rcv buff 0x7f16e18bcec8, pool rcvbuf, rqlen 1102 *** 2012-05-02 02:21:08.449 kclccctx: cleanup copy 0x7f16e1d94838 *** 2012-05-02 02:21:08.449 kcltouched: touch seconds 3271 *** 2012-05-02 02:21:08.449 kclgrantlk: req=48054 2012-05-02 02:21:08.449347 : [kjmpmsgi:compl][type 36][msg 0x7f16e14a4398][seq 177810.0][qtime 0][ptime 1119] WAIT #0: nam='gcs remote message' ela= 568 waittime=1 poll=0 event=0 obj#=0 tim=1335939668449962 2012-05-02 02:21:08.450001 : GSIPC:RCVD: ksxp msg 0x7f16e1bb22a0 sndr 1 seq 0.177811 type 32 tkts 0 2012-05-02 02:21:08.450024 : GSIPC:RCVD: watq msg 0x7f16e1bb22a0 sndr 1, seq 177811, type 32, tkts 0 2012-05-02 02:21:08.450043 : GSIPC:TKT: collect msg 0x7f16e1bb22a0 from 1 for rcvr -1, tickets 0 2012-05-02 02:21:08.450060 : kjbrcvdscn[0x0.1ae28e][from 1][idx 2012-05-02 02:21:08.450078 : kjbrcvdscn[no bscn <= rscn 0x0.1ae28e][from 1] 2012-05-02 02:21:08.450097 : GSIPC:TKT: dest (1:1) rtkt not acked 3 unassigned bufs 0 tkts 0 newbufs 0 2012-05-02 02:21:08.450116 : GSIPC:TKT: remove ctx dest (1:1) 2012-05-02 02:21:08.450136 : [kjmxmpm][type 32][seq 0.177811][msg 0x7f16e1bb22a0][from 1] 2012-05-02 02:21:08.450155 : kjbmpocr(0xb0.6)seq 0x1,reqid=0x23e,(client 0x9fff7b58,0x1)(from 1)(lseq xdf4) ???Instance 2??LMS???,???build cr block,??????Instance 1?????Current Block??????Instance 2??v$cr_block_server??????LIGHT_WORKS?????current block transfer??????,??????? CR server? Light Work Rule(Light Work Rule?8i Cr Server?????????,?Remote LMS?? build CR????????,resource holder?LMS???????block,????CR build If creating the consistent read version block involves too much work (such as reading blocks from disk), then the holder sends the block to the requestor, and the requestor completes the CR fabrication. The holder maintains a fairness counter of CR requests. After the fairness threshold is reached, the holder downgrades it to lock mode.)? ??????? CR Request ????Current Block?? ???:??????class?block,CR server??????? ??undo block?? undo header block?CR quest, LMS????Current Block, ????? ???? ??????? block cleanout? CR Version??????? ???????? data blocks, ??????? CR quest & CR received?(???????Light Work Rule,LMS"??"), ??Current Block??DownConvert???S lock,??LMS???????ship??current version?block? ??????? , ?????? ,???????DownConvert?????”_fairness_threshold“???200,????Xcurrent Block?????Scurrent, ????LMS?????Current Version?Data Block: SQL> show parameter fair NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ _fairness_threshold integer 200 Instance 1: SQL> update test set id=id+1 where id=4; 1 row updated. Instance 2: SQL> update test set id=id+1 where id=2; 1 row updated. SQL> select state,cr_scn_bas from x$bh where file#=1 and dbablk=89233 and state!=0; STATE CR_SCN_BAS ---------- ---------- 1 0 3 1838166 ?Instance 1? ????,? ??instance 2? v$cr_block_server?? instance 1 SQL> select * from test; ID ---------- 10 3 instance 2: SQL> select state,cr_scn_bas from x$bh where file#=1 and dbablk=89233 and state!=0; STATE CR_SCN_BAS ---------- ---------- 1 0 3 1883707 8 0 SQL> select * from test; ID ---------- 10 3 SQL> select state,cr_scn_bas from x$bh where file#=1 and dbablk=89233 and state!=0; STATE CR_SCN_BAS ---------- ---------- 1 0 3 1883707 8 0 ................... SQL> / STATE CR_SCN_BAS ---------- ---------- 2 0 3 1883707 3 1883695 repeat cr request on Instance 1 SQL> / STATE CR_SCN_BAS ---------- ---------- 8 0 3 1883707 3 1883695 ??????_fairness_threshold????????,?????200 ????????CR serve??Downgrade?lock, ????data block? CR Request????Receive? Current Block?

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Multi-Threaded Application vs. Single Threaded Application

Why would we use a multi threaded application vs. a single threaded application? First we must define multithreading. Multithreading is a feature of an operating system that allows programs to run subcomponents or threads in parallel. Typically most applications only need to use one thread because they do not perform time consuming tasks. The use of multiple threads allows an application to distribute long running tasks so that they can be executed in parallel. This gives the user the perceived appearance that the application is working faster due to the fact that while one thread is waiting on an IO process the remaining tasks can make use of the available CPU. The allows working threads to execute in tandem so that they can be competed sooner. Multithreading Benefits Improved responsiveness — Users usually report improved responsiveness compared to single thread applications. Faster applications — Multiple threads can lead to improved application performance. Prioritization — Threads can be assigned a priority which would allow higher priority tasks to take precedence over lower priority tasks. Single Threading Benefits Programming and debugging —These activities are easier compared to multithreaded applications due to the reduced complexity Less Overhead — Threads add overhead to an application When developing multi-threaded applications, the following must be considered. Deadlocks occur when two threads hold a monitor that the other one requires. In essence each task is blocking the other and both tasks are waiting for the other monitor to be released. This forces an application to hang or deadlock. Resource allocation is used to prevent deadlocks because the system determines if approving the resource request will render the system in an unsafe state. An unsafe state could result in a deadlock. The system only approves requests that will lead to safe states. Thread Synchronization is used when multiple threads use the same instance of an object. The threads accessing the object can then be locked and then synchronized so that each task can interact with the static object on at a time.

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Easy way to update models in your ASP.NET MVC business layer

- by rajbk

Brad Wilson just mentioned there is a static class ModelCopier that has a static method CopyModel(object from, object to) in the MVC Futures library. It uses reflection to match properties with the same name and compatible types. In short, instead of manually copying over properties as shown here: public void Save(EmployeeViewModel employeeViewModel){ var employee = (from emp in dataContext.Employees where emp.EmployeeID == employeeViewModel.EmployeeID select emp).SingleOrDefault(); if (employee != null) { employee.Address = employeeViewModel.Address; employee.Salary = employeeViewModel.Salary; employee.Title = employeeViewModel.Title; } dataContext.SubmitChanges();} you can use the method like so: public void Save(EmployeeViewModel employeeViewModel){ var employee = (from emp in dataContext.Employees where emp.EmployeeID == employeeViewModel.EmployeeID select emp).SingleOrDefault(); if (employee != null) { ModelCopier.CopyModel(employeeViewModel, employee); } dataContext.SubmitChanges();} Beautiful, isn’t it?

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Using a WCF Message Inspector to extend AppFabric Monitoring

- by Shawn Cicoria

I read through Ron Jacobs post on Monitoring WCF Data Services with AppFabric http://blogs.msdn.com/b/endpoint/archive/2010/06/09/tracking-wcf-data-services-with-windows-server-appfabric.aspx What is immediately striking are 2 things – it’s so easy to get monitoring data into a viewer (AppFabric Dashboard) w/ very little work. And the 2nd thing is, why can’t this be a WCF message inspector on the dispatch side. So, I took the base class WCFUserEventProvider that’s located in the WCF/WF samples [1] in the following path, \WF_WCF_Samples\WCF\Basic\Management\AnalyticTraceExtensibility\CS\WCFAnalyticTracingExtensibility\ and then created a few classes that project the injection as a IEndPointBehavior There are just 3 classes to drive injection of the inspector at runtime via config: IDispatchMessageInspector implementation BehaviorExtensionElement implementation IEndpointBehavior implementation The full source code is below with a link to the solution file here: [Solution File] using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.ServiceModel.Dispatcher; using System.ServiceModel.Channels; using System.ServiceModel; using System.ServiceModel.Configuration; using System.ServiceModel.Description; using Microsoft.Samples.WCFAnalyticTracingExtensibility; namespace Fabrikam.Services { public class AppFabricE2EInspector : IDispatchMessageInspector { static WCFUserEventProvider evntProvider = null; static AppFabricE2EInspector() { evntProvider = new WCFUserEventProvider(); } public object AfterReceiveRequest( ref Message request, IClientChannel channel, InstanceContext instanceContext) { OperationContext ctx = OperationContext.Current; var opName = ctx.IncomingMessageHeaders.Action; evntProvider.WriteInformationEvent("start", string.Format("operation: {0} at address {1}", opName, ctx.EndpointDispatcher.EndpointAddress)); return null; } public void BeforeSendReply(ref System.ServiceModel.Channels.Message reply, object correlationState) { OperationContext ctx = OperationContext.Current; var opName = ctx.IncomingMessageHeaders.Action; evntProvider.WriteInformationEvent("end", string.Format("operation: {0} at address {1}", opName, ctx.EndpointDispatcher.EndpointAddress)); } } public class AppFabricE2EBehaviorElement : BehaviorExtensionElement { #region BehaviorExtensionElement /// <summary> /// Gets the type of behavior. /// </summary> /// <value></value> /// <returns>The type that implements the end point behavior<see cref="T:System.Type"/>.</returns> public override Type BehaviorType { get { return typeof(AppFabricE2EEndpointBehavior); } } /// <summary> /// Creates a behavior extension based on the current configuration settings. /// </summary> /// <returns>The behavior extension.</returns> protected override object CreateBehavior() { return new AppFabricE2EEndpointBehavior(); } #endregion BehaviorExtensionElement } public class AppFabricE2EEndpointBehavior : IEndpointBehavior //, IServiceBehavior { #region IEndpointBehavior public void AddBindingParameters(ServiceEndpoint endpoint, BindingParameterCollection bindingParameters) {} public void ApplyClientBehavior(ServiceEndpoint endpoint, ClientRuntime clientRuntime) { throw new NotImplementedException(); } public void ApplyDispatchBehavior(ServiceEndpoint endpoint, EndpointDispatcher endpointDispatcher) { endpointDispatcher.DispatchRuntime.MessageInspectors.Add(new AppFabricE2EInspector()); } public void Validate(ServiceEndpoint endpoint) { ; } #endregion IEndpointBehavior } } [1] http://www.microsoft.com/downloads/details.aspx?FamilyID=35ec8682-d5fd-4bc3-a51a-d8ad115a8792&displaylang=en

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How can you explain "beautiful code" to a non-programmer?

- by Daniel Vandersluis

When speaking with a non-programmer friend, I happened to mention the concept of "beautiful code" and she wanted to understand what that meant, but I was at a bit of a loss as to how to explain it to someone who would have no context whatsoever. When all code looks like gibberish to someone anyways, how can you explain what makes one piece of code prettier than another? Analogies could be useful too.

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