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  • 30 seconds from File|New to a new CRUD Silverlight application with Teleriks new LINQ Implementation

    Last month Telerik released its new LINQ implementation and last week we released the new Data Services Wizard for Telerik OpenAccess, which supports both traditional OpenAccess entities and the new LINQ implementation. I will a walk you through the process where you can connect to a database, add a new domain model, wrap it in a new WCF Data Services (Astoria) service, and add a CRUD enabled Silverlight application. All in 30 seconds! Step 1: Build your Domain Model (20 seconds) Open Visual Studio 2010 RTM (or 2008) and add a new ASP.NET project. Right click on the project and select Add|New Item and choose Telerk OpenAccess Domain Model from the item template list. The Visual Entity Designer wizard comes up. Select the database server you are using in the first screen (SQL Server, Oracle, SQL Azure, MySQL, etc) and then also build your database connection string. Next select the tables, views, and stored procedures you want ...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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  • Working with Timelines with LINQ to Twitter

    - by Joe Mayo
    When first working with the Twitter API, I thought that using SinceID would be an effective way to page through timelines. In practice it doesn’t work well for various reasons. To explain why, Twitter published an excellent document that is a must-read for anyone working with timelines: Twitter Documentation: Working with Timelines This post shows how to implement the recommended strategies in that document by using LINQ to Twitter. You should read the document in it’s entirety before moving on because my explanation will start at the bottom and work back up to the top in relation to the Twitter document. What follows is an explanation of SinceID, MaxID, and how they come together to help you efficiently work with Twitter timelines. The Role of SinceID Specifying SinceID says to Twitter, “Don’t return tweets earlier than this”. What you want to do is store this value after every timeline query set so that it can be reused on the next set of queries.  The next section will explain what I mean by query set, but a quick explanation is that it’s a loop that gets all new tweets. The SinceID is a backstop to avoid retrieving tweets that you already have. Here’s some initialization code that includes a variable named sinceID that will be used to populate the SinceID property in subsequent queries: // last tweet processed on previous query set ulong sinceID = 210024053698867204; ulong maxID; const int Count = 10; var statusList = new List<status>(); Here, I’ve hard-coded the sinceID variable, but this is where you would initialize sinceID from whatever storage you choose (i.e. a database). The first time you ever run this code, you won’t have a value from a previous query set. Initially setting it to 0 might sound like a good idea, but what if you’re querying a timeline with lots of tweets? Because of the number of tweets and rate limits, your query set might take a very long time to run. A caveat might be that Twitter won’t return an entire timeline back to Tweet #0, but rather only go back a certain period of time, the limits of which are documented for individual Twitter timeline API resources. So, to initialize SinceID at too low of a number can result in a lot of initial tweets, yet there is a limit to how far you can go back. What you’re trying to accomplish in your application should guide you in how to initially set SinceID. I have more to say about SinceID later in this post. The other variables initialized above include the declaration for MaxID, Count, and statusList. The statusList variable is a holder for all the timeline tweets collected during this query set. You can set Count to any value you want as the largest number of tweets to retrieve, as defined by individual Twitter timeline API resources. To effectively page results, you’ll use the maxID variable to set the MaxID property in queries, which I’ll discuss next. Initializing MaxID On your first query of a query set, MaxID will be whatever the most recent tweet is that you get back. Further, you don’t know what MaxID is until after the initial query. The technique used in this post is to do an initial query and then use the results to figure out what the next MaxID will be.  Here’s the code for the initial query: var userStatusResponse = (from tweet in twitterCtx.Status where tweet.Type == StatusType.User && tweet.ScreenName == "JoeMayo" && tweet.SinceID == sinceID && tweet.Count == Count select tweet) .ToList(); statusList.AddRange(userStatusResponse); // first tweet processed on current query maxID = userStatusResponse.Min( status => ulong.Parse(status.StatusID)) - 1; The query above sets both SinceID and Count properties. As explained earlier, Count is the largest number of tweets to return, but the number can be less. A couple reasons why the number of tweets that are returned could be less than Count include the fact that the user, specified by ScreenName, might not have tweeted Count times yet or might not have tweeted at least Count times within the maximum number of tweets that can be returned by the Twitter timeline API resource. Another reason could be because there aren’t Count tweets between now and the tweet ID specified by sinceID. Setting SinceID constrains the results to only those tweets that occurred after the specified Tweet ID, assigned via the sinceID variable in the query above. The statusList is an accumulator of all tweets receive during this query set. To simplify the code, I left out some logic to check whether there were no tweets returned. If  the query above doesn’t return any tweets, you’ll receive an exception when trying to perform operations on an empty list. Yeah, I cheated again. Besides querying initial tweets, what’s important about this code is the final line that sets maxID. It retrieves the lowest numbered status ID in the results. Since the lowest numbered status ID is for a tweet we already have, the code decrements the result by one to keep from asking for that tweet again. Remember, SinceID is not inclusive, but MaxID is. The maxID variable is now set to the highest possible tweet ID that can be returned in the next query. The next section explains how to use MaxID to help get the remaining tweets in the query set. Retrieving Remaining Tweets Earlier in this post, I defined a term that I called a query set. Essentially, this is a group of requests to Twitter that you perform to get all new tweets. A single query might not be enough to get all new tweets, so you’ll have to start at the top of the list that Twitter returns and keep making requests until you have all new tweets. The previous section showed the first query of the query set. The code below is a loop that completes the query set: do { // now add sinceID and maxID userStatusResponse = (from tweet in twitterCtx.Status where tweet.Type == StatusType.User && tweet.ScreenName == "JoeMayo" && tweet.Count == Count && tweet.SinceID == sinceID && tweet.MaxID == maxID select tweet) .ToList(); if (userStatusResponse.Count > 0) { // first tweet processed on current query maxID = userStatusResponse.Min( status => ulong.Parse(status.StatusID)) - 1; statusList.AddRange(userStatusResponse); } } while (userStatusResponse.Count != 0 && statusList.Count < 30); Here we have another query, but this time it includes the MaxID property. The SinceID property prevents reading tweets that we’ve already read and Count specifies the largest number of tweets to return. Earlier, I mentioned how it was important to check how many tweets were returned because failing to do so will result in an exception when subsequent code runs on an empty list. The code above protects against this problem by only working with the results if Twitter actually returns tweets. Reasons why there wouldn’t be results include: if the first query got all the new tweets there wouldn’t be more to get and there might not have been any new tweets between the SinceID and MaxID settings of the most recent query. The code for loading the returned tweets into statusList and getting the maxID are the same as previously explained. The important point here is that MaxID is being reset, not SinceID. As explained in the Twitter documentation, paging occurs from the newest tweets to oldest, so setting MaxID lets us move from the most recent tweets down to the oldest as specified by SinceID. The two loop conditions cause the loop to continue as long as tweets are being read or a max number of tweets have been read.  Logically, you want to stop reading when you’ve read all the tweets and that’s indicated by the fact that the most recent query did not return results. I put the check to stop after 30 tweets are reached to keep the demo from running too long – in the console the response scrolls past available buffer and I wanted you to be able to see the complete output. Yet, there’s another point to be made about constraining the number of items you return at one time. The Twitter API has rate limits and making too many queries per minute will result in an error from twitter that LINQ to Twitter raises as an exception. To use the API properly, you’ll have to ensure you don’t exceed this threshold. Looking at the statusList.Count as done above is rather primitive, but you can implement your own logic to properly manage your rate limit. Yeah, I cheated again. Summary Now you know how to use LINQ to Twitter to work with Twitter timelines. After reading this post, you have a better idea of the role of SinceID - the oldest tweet already received. You also know that MaxID is the largest tweet ID to retrieve in a query. Together, these settings allow you to page through results via one or more queries. You also understand what factors affect the number of tweets returned and considerations for potential error handling logic. The full example of the code for this post is included in the downloadable source code for LINQ to Twitter.   @JoeMayo

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  • [LINQ] Master &ndash; Detail Same Record(II)

    - by JTorrecilla
    In my previous post, I introduced my problem, but I didn’t explain the problem with Entity Framework When you try the solution indicated you will take the following error: LINQ to Entities don’t recognize the method 'System.String Join(System.String, System.Collections.Generic.IEnumerable`1[System.String])’ of the method, and this method can’t be translated into a stored expression. The query that produces that error was: 1: var consulta = (from TCabecera cab in 2: contexto_local.TCabecera 3: let Detalle = (from TDetalle detalle 4: in cab.TDetalle 5: select detalle.Nombre) 6: let Nombres = string.Join(",",Detalle ) 7: select new 8: { 9: cab.Campo1, 10: cab.Campo2, 11: Nombres 12: }).ToList(); 13: grid.DataSource=consulta;   Why is this error happening? This error happens when the query couldn’t be translated into T-SQL. Solutions? To quit that error, we need to execute the query on 2 steps: 1: var consulta = (from TCabecera cab in 2: contexto_local.TCabecera 3: let Detalle = (from TDetalle detalle 4: in cab.TDetalle 5: select detalle.Nombre) 6: select new 7: { 8: cab.Campo1, 9: cab.Campo2, 10: Detalle 11: }).ToList(); 12: var consulta2 = (from dato in consulta 13: let Nombes = string.Join(",",dato.Detalle) 14: select new 15: { 16: dato.Campo1, 17: dato.Campo2, 18: Nombres 19: }; 20: grid.DataSource=consulta2.ToList(); Curiously This problem happens with Entity Framework but, the same problem can’t be reproduced on LINQ – To – SQL, that it works fine in one unique step. Hope It’s helpful Best Regards

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  • [LINQ] Master&ndash;Detail Same Record (I)

    - by JTorrecilla
    PROBLEM Firstly, I am working on a project based on LINQ, EF, and C# with VS2010. The following Table shows what I have and what I want to show. Header C1 C2 C3 1 P1 01/01/2011 2 P2 01/02/2011 Details 1 1 D1 2 1 D2 3 1 D3 4 2 D1 5 2 D4 Expected Results 1 P1 01/01/2011 D1, D2, D3 2 P2 01/02/2011 D1,D4   IDEAS At the begin I got 3 possible ways: - Doing inside the DB:  It could be achieved from DB with a CURSOR in a Stored Procedure. - Doing from .NET with LOOPS. - Doing with LINQ (I love it!!) FIRST APROX Example with a simple CLASS with a LIST: With and Employee Class that acts as Header Table: 1: public class Employee 2: { 3: public Employee () { } 4: public Int32 ID { get; set; } 5: public String FirstName{ get; set; } 6: public String LastName{ get; set; } 7: public List<string> Numbers{ get; set; } // Acts as Details Table 8: } We can show all numbers contained by Employee: 1: List<Employee > listado = new List<Employee >(); 2: //Fill Listado 3: var query= from Employee em in listado 4: let Nums= string.Join(";", em.Numbers) 5: select new { 6: em.Name, 7: Nums 8: }; The “LET” operator allows us to host the results of “Join” of the Numbers List of the Employee Class. A little example. ASAP I will post the second part to achieve the same with Entity Framework. Best Regards

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  • JPA thinks I'm deleting a detached object

    - by Steve
    So, I've got a DAO that I used to load and save my domain objects using JPA. I finally managed to get the transaction stuff working (with a bunch of help from the folks here...), now I've got another issue. In my test case, I call my DAO to load a domain object with a given id, check that it got loaded and then call the same DAO to delete the object I just loaded. When I do that I get the following: java.lang.IllegalArgumentException: Removing a detached instance mil.navy.ndms.conops.common.model.impl.jpa.Group#10 at org.hibernate.ejb.event.EJB3DeleteEventListener.performDetachedEntityDeletionCheck(EJB3DeleteEventListener.java:45) at org.hibernate.event.def.DefaultDeleteEventListener.onDelete(DefaultDeleteEventListener.java:108) at org.hibernate.event.def.DefaultDeleteEventListener.onDelete(DefaultDeleteEventListener.java:74) at org.hibernate.impl.SessionImpl.fireDelete(SessionImpl.java:794) at org.hibernate.impl.SessionImpl.delete(SessionImpl.java:772) at org.hibernate.ejb.AbstractEntityManagerImpl.remove(AbstractEntityManagerImpl.java:253) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:48) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37) at java.lang.reflect.Method.invoke(Method.java:600) at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:180) at $Proxy27.remove(Unknown Source) at mil.navy.ndms.conops.common.dao.impl.jpa.GroupDao.delete(GroupDao.java:499) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:48) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37) at java.lang.reflect.Method.invoke(Method.java:600) at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:304) at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:182) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:149) at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:106) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171) at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204) at $Proxy28.delete(Unknown Source) at mil.navy.ndms.conops.common.dao.impl.jpa.GroupDaoTest.testGroupDaoSave(GroupDaoTest.java:89) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:48) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37) at java.lang.reflect.Method.invoke(Method.java:600) at junit.framework.TestCase.runTest(TestCase.java:164) at junit.framework.TestCase.runBare(TestCase.java:130) at junit.framework.TestResult$1.protect(TestResult.java:106) at junit.framework.TestResult.runProtected(TestResult.java:124) at junit.framework.TestResult.run(TestResult.java:109) at junit.framework.TestCase.run(TestCase.java:120) at junit.framework.TestSuite.runTest(TestSuite.java:230) at junit.framework.TestSuite.run(TestSuite.java:225) at org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestReference.run(JUnit3TestReference.java:130) at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:460) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:673) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:386) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196) Now given that I'm using the same DAO instance, and I've not changed EntityManagers (unless Spring does so without letting me know), how can this be a detached object? My DAO code looks like this: public class GenericJPADao implements IWebDao, IDao, IDaoUtil { private static Logger logger = Logger.getLogger (GenericJPADao.class); protected Class voClass; @PersistenceContext(unitName = "CONOPS_PU") protected EntityManagerFactory emf; @PersistenceContext(unitName = "CONOPS_PU") protected EntityManager em; public GenericJPADao() { super ( ); ParameterizedType genericSuperclass = (ParameterizedType) getClass ( ).getGenericSuperclass ( ); this.voClass = (Class) genericSuperclass.getActualTypeArguments ( )[1]; } ... public void delete (INTFC modelObj, EntityManager em) { em.remove (modelObj); } @SuppressWarnings("unchecked") public INTFC findById (Long id) { return ((INTFC) em.find (voClass, id)); } } The test case code looks like: IGroup loadedGroup = dao.findById (group.getId ( )); assertNotNull (loadedGroup); assertEquals (group.getId ( ), loadedGroup.getId ( )); dao.delete (loadedGroup); // - This generates the above exception loadedGroup = dao.findById (group.getId ( )); assertNull(loadedGroup); Can anyone tell me what I'm doing wrong here? Thanks

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  • Domain Driven Design And The Entity Framework

    - by Hossein
    hi, I'm new to DDD and i want to use entity framework v4.0 (shipped with .net 4.0) in my new project. since i have few time to learn DDD and entity framework, which books are good for me to read first?! i'm going to first read Domain-Driven Design Tackling Complexity in the Heart of Software by Eric Evan and next Pro Entity Framework 4.0 (Apress Scott Klein)... the problem here is Eric Evan's book is too abstract,I want to know if the Pro Entity framework 4.0 is complete enough i just skip the first book! in the end recommend me some good books in DDD and Entity Framework Thanks

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  • Spring/Hibernate: InvocationTargetException when deleting entity

    - by niklassaers
    I'm sorry if this question is a bit vague, but I'm quite confused. I've got a controller that calls a service to delete an entity and then create an entity in its place. In the service, I've got my DAO, and my entity, and I want to delete my entity, so I call DAO.delete(entity); Then, seemingly out of nowhere, I get an InvocationTargetException. The parameters here are: method: public org.springframework.web.servlet.ModelAndView tld.myproject.view.web.controller.MyController.replaceEntity(org.springframework.web.multipart.MultipartFile,javax.servlet.http.HttpServletRequest) target: tld.myproject.view.web.controller.MyController@185918e args: [org.springframework.web.multipart.commons.CommonsMultipartFile@14812a6, org.springframework.web.multipart.support.DefaultMultipartHttpServletRequest@c08a64] ex: java.lang.reflect.InvocationTargetException private Object doInvokeMethod(Method method, Object target, Object[] args) throws Exception { ReflectionUtils.makeAccessible(method); try { return method.invoke(target, args); } catch (InvocationTargetException ex) { ReflectionUtils.rethrowException(ex.getTargetException()); } throw new IllegalStateException("Should never get here"); } Does anyone have a suggestion to what's going on? Anything I can use in my debugging? Cheers Nik

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  • How to persist every new entity?

    - by simpatico
    I expect every instantiated entity to correspond to a tuple (& co) in the database. In the examples I see around, one always instantiates the entity (via a constructor) and then calls persist with that entity. I find this error-prone, and was wondering if it wasn't possible to have every instantiated entity automatically managed/persisted/reflected to the database (at least intended to). This also seems to prevent me from persisting instance variable entities. I.e. I've an entity which instantiates another (entities it has an association with) in its constructor.

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  • ASP.NET MVC & EF4 Entity Framework - Are there any performance concerns in using the entities vs retrieving only the fields i need?

    - by Ant
    Lets say we have 3 tables, Users, Products, Purchases. There is a view that needs to display the purchases made by a user. I could lookup the data required by doing: from p in DBSet<Purchases>.Include("User").Include("Product") select p; However, I am concern that this may have a performance impact because it will retrieve the full objects. Alternatively, I could select only the fields i need: from p in DBSet<Purchases>.Include("User").Include("Product") select new SimplePurchaseInfo() { UserName = p.User.name, Userid = p.User.Id, ProductName = p.Product.Name ... etc }; So my question is: Whats the best practice in doing this? == EDIT Thanks for all the replies. [QUESTION 1]: I want to know whether all views should work with flat ViewModels with very specific data for that view, or should the ViewModels contain the entity objects. Real example: User reviews Products var query = from dr in productRepository.FindAllReviews() where dr.User.UserId = 'userid' select dr; string sql = ((ObjectQuery)query).ToTraceString(); SELECT [Extent1].[ProductId] AS [ProductId], [Extent1].[Comment] AS [Comment], [Extent1].[CreatedTime] AS [CreatedTime], [Extent1].[Id] AS [Id], [Extent1].[Rating] AS [Rating], [Extent1].[UserId] AS [UserId], [Extent3].[CreatedTime] AS [CreatedTime1], [Extent3].[CreatorId] AS [CreatorId], [Extent3].[Description] AS [Description], [Extent3].[Id] AS [Id1], [Extent3].[Name] AS [Name], [Extent3].[Price] AS [Price], [Extent3].[Rating] AS [Rating1], [Extent3].[ShopId] AS [ShopId], [Extent3].[Thumbnail] AS [Thumbnail], [Extent3].[Creator_UserId] AS [Creator_UserId], [Extent4].[Comment] AS [Comment1], [Extent4].[DateCreated] AS [DateCreated], [Extent4].[DateLastActivity] AS [DateLastActivity], [Extent4].[DateLastLogin] AS [DateLastLogin], [Extent4].[DateLastPasswordChange] AS [DateLastPasswordChange], [Extent4].[Email] AS [Email], [Extent4].[Enabled] AS [Enabled], [Extent4].[PasswordHash] AS [PasswordHash], [Extent4].[PasswordSalt] AS [PasswordSalt], [Extent4].[ScreenName] AS [ScreenName], [Extent4].[Thumbnail] AS [Thumbnail1], [Extent4].[UserId] AS [UserId1], [Extent4].[UserName] AS [UserName] FROM [ProductReviews] AS [Extent1] INNER JOIN [Users] AS [Extent2] ON [Extent1].[UserId] = [Extent2].[UserId] LEFT OUTER JOIN [Products] AS [Extent3] ON [Extent1].[ProductId] = [Extent3].[Id] LEFT OUTER JOIN [Users] AS [Extent4] ON [Extent1].[UserId] = [Extent4].[UserId] WHERE N'615005822' = [Extent2].[UserId] or from d in productRepository.FindAllProducts() from dr in d.ProductReviews where dr.User.UserId == 'userid' orderby dr.CreatedTime select new ProductReviewInfo() { product = new SimpleProductInfo() { Id = d.Id, Name = d.Name, Thumbnail = d.Thumbnail, Rating = d.Rating }, Rating = dr.Rating, Comment = dr.Comment, UserId = dr.UserId, UserScreenName = dr.User.ScreenName, UserThumbnail = dr.User.Thumbnail, CreateTime = dr.CreatedTime }; SELECT [Extent1].[Id] AS [Id], [Extent1].[Name] AS [Name], [Extent1].[Thumbnail] AS [Thumbnail], [Extent1].[Rating] AS [Rating], [Extent2].[Rating] AS [Rating1], [Extent2].[Comment] AS [Comment], [Extent2].[UserId] AS [UserId], [Extent4].[ScreenName] AS [ScreenName], [Extent4].[Thumbnail] AS [Thumbnail1], [Extent2].[CreatedTime] AS [CreatedTime] FROM [Products] AS [Extent1] INNER JOIN [ProductReviews] AS [Extent2] ON [Extent1].[Id] = [Extent2].[ProductId] INNER JOIN [Users] AS [Extent3] ON [Extent2].[UserId] = [Extent3].[UserId] LEFT OUTER JOIN [Users] AS [Extent4] ON [Extent2].[UserId] = [Extent4].[UserId] WHERE N'userid' = [Extent3].[UserId] ORDER BY [Extent2].[CreatedTime] ASC [QUESTION 2]: Whats with the ugly outer joins?

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  • Transaction on Entity FrameWork Refactoring and best performance how can i?

    - by programmerist
    i try to use transaction in Entity FrameWork. i have 3 tables Personel, Prim, Finans. in Prim table you look SatisTutari (int) if i add data in SatisTutari.Text instead of int value adding float value. Trannsaction must be run! Everything is ok but how can i refactoring or give best performance or best writing Transaction coding! i have 3 table so i have 3 entities: CREATE TABLE Personel (PersonelID integer PRIMARY KEY identity not null, Ad varchar(30), Soyad varchar(30), Meslek varchar(100), DogumTarihi datetime, DogumYeri nvarchar(100), PirimToplami float); Go create TABLE Prim (PrimID integer PRIMARY KEY identity not null, PersonelID integer Foreign KEY references Personel(PersonelID), SatisTutari int, Prim float, SatisTarihi Datetime); Go CREATE TABLE Finans (ID integer PRIMARY KEY identity not null, Tutar float); Personel, Prim,Finans my tables. if you look Prim table you can see Prim value float value if i write a textbox not float value my transaction must run. protected void btnSave_Click(object sender, EventArgs e) { using (TestEntities testCtx = new TestEntities()) { using (TransactionScope scope = new TransactionScope()) { Personel personel = new Personel(); Prim prim = new Prim(); Finans finans = new Finans(); //-----------------------------------------------------------------------Step 1 personel.Ad = txtName.Text; personel.Soyad = txtSurName.Text; personel.Meslek = txtMeslek.Text; personel.DogumTarihi = DateTime.Parse(txtSatisTarihi.Text); personel.DogumYeri = txtDogumYeri.Text; personel.PirimToplami = float.Parse(txtPrimToplami.Text); testCtx.AddToPersonel(personel); testCtx.SaveChanges(); //----------------------------------------------------------------------- step 2 prim.PersonelID = personel.PersonelID; prim.SatisTutari = int.Parse(txtSatisTutari.Text); prim.SatisTarihi = DateTime.Parse(txtSatisTarihi.Text); prim.Prim1 = double.Parse(txtPrim.Text); finans.Tutar = prim.SatisTutari * prim.Prim1; testCtx.AddToPrim(prim); testCtx.SaveChanges(); //----------------------------------------------------------------------- step 3 lblTutar.Text = finans.Tutar.Value.ToString(); testCtx.AddToFinans(finans); testCtx.SaveChanges(); scope.Complete(); } } How can i rearrange codes. i need best practice refactoring and best solution for reading easly and performance!!!

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  • MVC Entity Framework: Cannot open user default database. Login failed.

    - by Michael
    This type of stuff drives me nuts. I'm having trouble finding the exact issue that I'm having, maybe I just don't know the terminology. Anyway, I had a working website using MVC and Entity Framework, but then I coded an error in a partial view page (ascx). Then all of a sudden I started to get this message. Cannot open user default database. Login failed. Login failed for user 'NT AUTHORITY\SYSTEM' I've found plenty of suggestions about opening SQL Server Management Studio, Double Click on Security, Double Click on Logins, Double click on NT AUTHORITY\SYSTEM and then double click on User Mapping. In this view I'm suppose to check the box for my database so that this user is mapped to this login. However, since I created my database in Visio Studio 2008 as part of my solution, it doesn't show up to allow me to click on it. So what do I do now? What drives me nuts is that everything was working fine. I was using my computer name to access the website and everything was working fine until the coding error. I've fix the error but still getting the error. I should also mention that this error started yesterday too around the same time but later cleared itself up. If I use localhost to access the site, it works just fine. IIS7 configuration for my website: Application Pool = DefaultAppPool Physical Path Credentials Logon = ClearText With in connection strings. I do see the one for my database in this solution. Entry Type is local metadata=res://*/Models.DataModel.csdl|res://*/Models.DataModel.ssdl|res://*/Models.DataModel.msl; provider=System.Data.SqlClient; provider connection string="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\FFBall.mdf;Integrated Security=True;User Instance=True;MultipleActiveResultSets=True" And somewhere I remember changing the identity from Network Service to LocalSystem. Because when I first stared I was getting this same message, but I changed this value and it started working. I saw that suggested somewhere too but I do not recall. Wait I remember now, I believe in IIS7, under Application Pools, DefaultAppPool identity is set to LocalSystem. Additional things I've tried. Restart the computer Recycle the application pool. Antivirus isn't running. Any help would be appreciated. Thank you in advance.

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  • Event Logging in LINQ C# .NET

    The first thing you'll want to do before using this code is to create a table in your database called TableHistory: CREATE TABLE [dbo].[TableHistory] (     [TableHistoryID] [int] IDENTITY NOT NULL ,     [TableName] [varchar] (50) NOT NULL ,     [Key1] [varchar] (50) NOT NULL ,     [Key2] [varchar] (50) NULL ,     [Key3] [varchar] (50) NULL ,     [Key4] [varchar] (50) NULL ,     [Key5] [varchar] (50) NULL ,     [Key6] [varchar] (50)NULL ,     [ActionType] [varchar] (50) NULL ,     [Property] [varchar] (50) NULL ,     [OldValue] [varchar] (8000) NULL ,     [NewValue] [varchar] (8000) NULL ,     [ActionUserName] [varchar] (50) NOT NULL ,     [ActionDateTime] [datetime] NOT NULL ) Once you have created the table, you'll need to add it to your custom LINQ class (which I will refer to as DboDataContext), thus creating the TableHistory class. Then, you'll need to add the History.cs file to your project. You'll also want to add the following code to your project to get the system date: public partial class DboDataContext{ [Function(Name = "GetDate", IsComposable = true)] public DateTime GetSystemDate() { MethodInfo mi = MethodBase.GetCurrentMethod() as MethodInfo; return (DateTime)this.ExecuteMethodCall(this, mi, new object[] { }).ReturnValue; }}private static Dictionary<type,> _cachedIL = new Dictionary<type,>();public static T CloneObjectWithIL<t>(T myObject){ Delegate myExec = null; if (!_cachedIL.TryGetValue(typeof(T), out myExec)) { // Create ILGenerator DynamicMethod dymMethod = new DynamicMethod("DoClone", typeof(T), new Type[] { typeof(T) }, true); ConstructorInfo cInfo = myObject.GetType().GetConstructor(new Type[] { }); ILGenerator generator = dymMethod.GetILGenerator(); LocalBuilder lbf = generator.DeclareLocal(typeof(T)); //lbf.SetLocalSymInfo("_temp"); generator.Emit(OpCodes.Newobj, cInfo); generator.Emit(OpCodes.Stloc_0); foreach (FieldInfo field in myObject.GetType().GetFields( System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.NonPublic)) { // Load the new object on the eval stack... (currently 1 item on eval stack) generator.Emit(OpCodes.Ldloc_0); // Load initial object (parameter) (currently 2 items on eval stack) generator.Emit(OpCodes.Ldarg_0); // Replace value by field value (still currently 2 items on eval stack) generator.Emit(OpCodes.Ldfld, field); // Store the value of the top on the eval stack into // the object underneath that value on the value stack. // (0 items on eval stack) generator.Emit(OpCodes.Stfld, field); } // Load new constructed obj on eval stack -> 1 item on stack generator.Emit(OpCodes.Ldloc_0); // Return constructed object. --> 0 items on stack generator.Emit(OpCodes.Ret); myExec = dymMethod.CreateDelegate(typeof(Func<t,>)); _cachedIL.Add(typeof(T), myExec); } return ((Func<t,>)myExec)(myObject);}I got both of the above methods off of the net somewhere (maybe even from CodeProject), but it's been long enough that I can't recall where I got them.Explanation of the History ClassThe History class records changes by creating a TableHistory record, inserting the values for the primary key for the table being modified into the Key1, Key2, ..., Key6 columns (if you have more than 6 values that make up a primary key on any table, you'll want to modify this), setting the type of change being made in the ActionType column (INSERT, UPDATE, or DELETE), old value and new value if it happens to be an update action, and the date and Windows identity of the user who made the change.Let's examine what happens when a call is made to the RecordLinqInsert method:public static void RecordLinqInsert(DboDataContext dbo, IIdentity user, object obj){ TableHistory hist = NewHistoryRecord(obj); hist.ActionType = "INSERT"; hist.ActionUserName = user.Name; hist.ActionDateTime = dbo.GetSystemDate(); dbo.TableHistories.InsertOnSubmit(hist);}private static TableHistory NewHistoryRecord(object obj){ TableHistory hist = new TableHistory(); Type type = obj.GetType(); PropertyInfo[] keys; if (historyRecordExceptions.ContainsKey(type)) { keys = historyRecordExceptions[type].ToArray(); } else { keys = type.GetProperties().Where(o => AttrIsPrimaryKey(o)).ToArray(); } if (keys.Length > KeyMax) throw new HistoryException("object has more than " + KeyMax.ToString() + " keys."); for (int i = 1; i <= keys.Length; i++) { typeof(TableHistory) .GetProperty("Key" + i.ToString()) .SetValue(hist, keys[i - 1].GetValue(obj, null).ToString(), null); } hist.TableName = type.Name; return hist;}protected static bool AttrIsPrimaryKey(PropertyInfo pi){ var attrs = from attr in pi.GetCustomAttributes(typeof(ColumnAttribute), true) where ((ColumnAttribute)attr).IsPrimaryKey select attr; if (attrs != null && attrs.Count() > 0) return true; else return false;}RecordLinqInsert takes as input a data context which it will use to write to the database, the user, and the LINQ object to be recorded (a single object, for instance, a Customer or Order object if you're using AdventureWorks). It then calls the NewHistoryRecord method, which uses LINQ to Objects in conjunction with the AttrIsPrimaryKey method to pull all the primary key properties, set the Key1-KeyN properties of the TableHistory object, and return the new TableHistory object. The code would be called in an application, like so: Continue span.fullpost {display:none;}

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  • Programação paralela no .NET Framework 4 – Parte I

    - by anobre
    Introdução O avanço de tecnologia nos últimos anos forneceu, a baixo custo, acesso  a workstations com inúmeros CPUs. Facilmente encontramos hoje máquinas clientes com 2, 4 e até 8 núcleos, sem considerar os “super-servidores” com até 36 processadores :) Da wikipedia: A Unidade central de processamento (CPU, de acordo com as iniciais em inglês) ou o processador é a parte de um sistema de computador que executa as instruções de um programa de computador, e é o elemento primordial na execução das funções de um computador. Este termo tem sido usado na indústria de computadores pelo menos desde o início dos anos 1960[1]. A forma, desenho e implementação de CPUs têm mudado dramaticamente desde os primeiros exemplos, mas o seu funcionamento fundamental permanece o mesmo. Fazendo uma analogia, seria muito interessante delegarmos tarefas no mundo real que podem ser executadas independentemente a pessoas diferentes, atingindo desta forma uma  maior performance / produtividade na sua execução. A computação paralela se baseia na idéia que um problema maior pode ser dividido em problemas menores, sendo resolvidos de forma paralela. Este pensamento é utilizado há algum tempo por HPC (High-performance computing), e através das facilidades dos últimos anos, assim como a preocupação com consumo de energia, tornaram esta idéia mais atrativa e de fácil acesso a qualquer ambiente. No .NET Framework A plataforma .NET apresenta um runtime, bibliotecas e ferramentas para fornecer uma base de acesso fácil e rápido à programação paralela, sem trabalhar diretamente com threads e thread pool. Esta série de posts irá apresentar todos os recursos disponíveis, iniciando os estudos pela TPL, ou Task Parallel Library. Task Parallel Library A TPL é um conjunto de tipos localizados no namespace System.Threading e System.Threading.Tasks, a partir da versão 4 do framework. A partir da versão 4 do framework, o TPL é a maneira recomendada para escrever código paralelo e multithreaded. http://msdn.microsoft.com/en-us/library/dd460717(v=VS.100).aspx Task Parallelism O termo “task parallelism”, ou em uma tradução live paralelismo de tarefas, se refere a uma ou mais tarefas sendo executadas de forma simultanea. Considere uma tarefa como um método. A maneira mais fácil de executar tarefas de forma paralela é o código abaixo: Parallel.Invoke(() => TrabalhoInicial(), () => TrabalhoSeguinte()); O que acontece de verdade? Por trás nos panos, esta instrução instancia de forma implícita objetos do tipo Task, responsável por representar uma operação assíncrona, não exatamente paralela: public class Task : IAsyncResult, IDisposable É possível instanciar Tasks de forma explícita, sendo uma alternativa mais complexa ao Parallel.Invoke. var task = new Task(() => TrabalhoInicial()); task.Start(); Outra opção de instanciar uma Task e já executar sua tarefa é: var t = Task<int>.Factory.StartNew(() => TrabalhoInicialComValor());var t2 = Task<int>.Factory.StartNew(() => TrabalhoSeguinteComValor()); A diferença básica entre as duas abordagens é que a primeira tem início conhecido, mais utilizado quando não queremos que a instanciação e o agendamento da execução ocorra em uma só operação, como na segunda abordagem. Data Parallelism Ainda parte da TPL, o Data Parallelism se refere a cenários onde a mesma operação deva ser executada paralelamente em elementos de uma coleção ou array, através de instruções paralelas For e ForEach. A idéia básica é pegar cada elemento da coleção (ou array) e trabalhar com diversas threads concomitantemente. A classe-chave para este cenário é a System.Threading.Tasks.Parallel // Sequential version foreach (var item in sourceCollection) { Process(item); } // Parallel equivalent Parallel.ForEach(sourceCollection, item => Process(item)); Complicado né? :) Demonstração Acesse aqui um vídeo com exemplos (screencast). Cuidado! Apesar da imensa vontade de sair codificando, tome cuidado com alguns problemas básicos de paralelismo. Neste link é possível conhecer algumas situações. Abraços.

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  • Design suggestions needed to create a MathBuilder framework

    - by Darf Zon
    Let explain what I'm trying to create. I'm creating a framework, the idea is to provide base classes to generate a math problem. Why do I need this framework? Because at first time, I realized when I create a new math problem I always do the same steps. Configuration settings such range numbers. For example if I'm developing multiplications, in beginner level only generate the first number between 2-5 or in advanced level, the first number will be between 6- 9, for example. Generate problem method. All the time I need to invoke a method like this to generate the problem. This one receives the configuration settings and generate the number according to them. And generate the object with the respective data. Validate the problem. Sometimes the problem generated is not valid. For example, supposed I'm creating fractions in most simplified, if I receive 2/4, the program should detect that this is not valid and must generate another like this one, 1/4. Load the view. All of them, have a custom view (please watch below the images). All of the problems must know how to CHECK if the user result is correct. All of this problems has answers. Some of them just require one answer, anothers may require more than one, so I guess a way to maintain flexibility to the developer has all the answers he wanna used. At the beginning I started using PRISM. Generate modules for each math problem was the idea and load it in the main system. I guess are the most important things of this idea. Let me showing some problems which I create in a WPF standalone program. Here I have a math problem about areas. When I generate the problem a set to the view the object and it draw it. In beginner level, I set in the configuration settings that just load square types. But in advance level, can load triangles and squares randomly. In this another, generate a binary problem like addition, subtraction, multiplication or division. Above just generate a single problem. The idea of this is to show a test o quiz, I mean get a worksheet (this I call as a collection of problems) where the user can answer it. I hope gets the idea with my ugly drawing. How to load this math problems? As I said above, I started using PRISM, and each module contains a math problem kind. This is a snapshot of my first demo. Below show the modules loaded, and center the respective configurations or levels. Until momment, I have no idea to start creating this software. I just know that I need a question | problem class, response class, user class. But I get lost about what properties should have to contain in it. Please give a little hand of this framework. I put much effort on this question, so if any isn't clear, let me know to clarify it.

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  • Starting to create a MathBuilder framework, help to start creating the design

    - by Darf Zon
    Let explain what I'm trying to create. I'm creating a framework, the idea is to provide base classes to generate a math problem. Why do I need this framework? Because at first time, I realized when I create a new math problem I always do the same steps. Configuration settings such range numbers. For example if I'm developing multiplications, in beginner level only generate the first number between 2-5 or in advanced level, the first number will be between 6- 9, for example. Generate problem method. All the time I need to invoke a method like this to generate the problem. This one receives the configuration settings and generate the number according to them. And generate the object with the respective data. Validate the problem. Sometimes the problem generated is not valid. For example, supposed I'm creating fractions in most simplified, if I receive 2/4, the program should detect that this is not valid and must generate another like this one, 1/4. Load the view. All of them, have a custom view (please watch below the images). All of the problems must know how to CHECK if the user result is correct. All of this problems has answers. Some of them just require one answer, anothers may require more than one, so I guess a way to maintain flexibility to the developer has all the answers he wanna used. At the beginning I started using PRISM. Generate modules for each math problem was the idea and load it in the main system. I guess are the most important things of this idea. Let me showing some problems which I create in a WPF standalone program. Here I have a math problem about areas. When I generate the problem a set to the view the object and it draw it. In beginner level, I set in the configuration settings that just load square types. But in advance level, can load triangles and squares randomly. In this another, generate a binary problem like addition, subtraction, multiplication or division. Above just generate a single problem. The idea of this is to show a test o quiz, I mean get a worksheet (this I call as a collection of problems) where the user can answer it. I hope gets the idea with my ugly drawing. How to load this math problems? As I said above, I started using PRISM, and each module contains a math problem kind. This is a snapshot of my first demo. Below show the modules loaded, and center the respective configurations or levels. Until momment, I have no idea to start creating this software. I just know that I need a question | problem class, response class, user class. But I get lost about what properties should have to contain in it. Please give a little hand of this framework. I put much effort on this question, so if any isn't clear, let me know to clarify it.

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  • Simple task framework - building software from reusable pieces

    - by RuslanD
    I'm writing a web service with several APIs, and they will be sharing some of the implementation code. In order not to copy-paste, I would like to ideally implement each API call as a series of tasks, which are executed in a sequence determined by the business logic. One obvious question is whether that's the best strategy for code reuse, or whether I can look at it in a different way. But assuming I want to go with tasks, several issues arise: What's a good task interface to use? How do I pass data computed in one task to another task in the sequence that might need it? In the past, I've worked with task interfaces like: interface Task<T, U> { U execute(T input); } Then I also had sort of a "task context" object which had getters and setters for any kind of data my tasks needed to produce or consume, and it gets passed to all tasks. I'm aware that this suffers from a host of problems. So I wanted to figure out a better way to implement it this time around. My current idea is to have a TaskContext object which is a type-safe heterogeneous container (as described in Effective Java). Each task can ask for an item from this container (task input), or add an item to the container (task output). That way, tasks don't need to know about each other directly, and I don't have to write a class with dozens of methods for each data item. There are, however, several drawbacks: Each item in this TaskContext container should be a complex type that wraps around the actual item data. If task A uses a String for some purpose, and task B uses a String for something entirely different, then just storing a mapping between String.class and some object doesn't work for both tasks. The other reason is that I can't use that kind of container for generic collections directly, so they need to be wrapped in another object. This means that, based on how many tasks I define, I would need to also define a number of classes for the task items that may be consumed or produced, which may lead to code bloat and duplication. For instance, if a task takes some Long value as input and produces another Long value as output, I would have to have two classes that simply wrap around a Long, which IMO can spiral out of control pretty quickly as the codebase evolves. I briefly looked at workflow engine libraries, but they kind of seem like a heavy hammer for this particular nail. How would you go about writing a simple task framework with the following requirements: Tasks should be as self-contained as possible, so they can be composed in different ways to create different workflows. That being said, some tasks may perform expensive computations that are prerequisites for other tasks. We want to have a way of storing the results of intermediate computations done by tasks so that other tasks can use those results for free. The task framework should be light, i.e. growing the code doesn't involve introducing many new types just to plug into the framework.

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  • How to query with the datetime value using LINQ to XML ?

    - by Shailesh Jaiswal
    I am developing window phone 7 application in silverlight. I am new to the silverlight. I am also new to LINQ to XML. In my application the user select the date & submit some transaction details into the application. The details gets stored in XML File. I am using the custom date control in my application for the date selection as follows private void DatePicker_ValueChanged(object sender, DateTimeValueChangedEventArgs e) { AppObj = Application.Current as App; AppObj.date = (DateTime)EntryDate.Value; } Then the value of AppObj.date gets stored in the XML file. Sometimes I use the DateTime.Now to store the date in the XML File. Now I want to generate the report of submitted transaction details by querying through LINQ to XML. I want to generate the report for today's date, current week & current month. For this purpose I am using the following code public void GetTransactionObjects(String strXMLFile, DateTime VDateTime) { XDocument doc = null; XMLFileManager XMLDocObj = new XMLFileManager(); doc = XMLDocObj.LoadXMLFile(strXMLFile); var vTransaction = from s in doc.Descendants("Transaction") .Where(x => x.Element("Current_Date").Value == VDateTime.ToShortDateString()) select new Transaction(s); this.Clear(); AddRange(vTransaction); } The Transaction class contains the following constructor. public Transaction(XElement xElement) { Transaction_ID = Convert.ToInt32(xElement.Element("Transaction_ID").Value.ToString()); TransactionType_ID = Convert.ToInt32(xElement.Element("TransactionType_ID").Value.ToString()); Alphabet_ID = Convert.ToInt32(xElement.Element("Alphabet_ID").Value.ToString()); ID = Convert.ToInt32(xElement.Element("ID").Value.ToString()); SubCategory_ID = Convert.ToInt32(xElement.Element("SubCategory_ID").Value.ToString()); Item_ID = Convert.ToInt32(xElement.Element("Item_ID").Value.ToString()); Currency_ID = Convert.ToInt32(xElement.Element("Currency_ID").Value.ToString()); InputTypeMethod_ID = Convert.ToInt32(xElement.Element("InputTypeMethod_ID").Value.ToString()); Principle = Convert.ToInt32(xElement.Element("InputTypeMethod_ID").Value.ToString()); Interest = Convert.ToInt32(xElement.Element("Interest").Value.ToString()); ROI = Convert.ToInt32(xElement.Element("InputTypeMethod_ID").Value.ToString()); Amount = Convert.ToInt32(xElement.Element("InputTypeMethod_ID").Value.ToString()); Current_Date = Convert.ToDateTime(xElement.Element("Current_Date").Value.ToString()); } In the XML File the value gets stored for date & time. The value gets stored as follows 0 0 3 0 0 0 3 0 0 0 0 5000 2010-12-31T18:08:23.433+05:30 Look at the node <Current_Date>2010-12-31T18:08:23.433+05:30</Current_Date> The date format is yyyy-mm-dd. Now how should I write the following query to get all the submitted transaction details for today's date ? var vTransaction = from s in doc.Descendants("Transaction") .Where(x => x.Element("Current_Date").Value == VDateTime.ToShortDateString()) select new Transaction(s); Similarly how should I write the query to get all the transaction details for the current week & current month? Can you please provide me any code or link through which I can resolve the above issue ? If I am doing anything wrong then please guide me.

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  • .NET 3.5 Client Framework redistributable ?

    - by Holli
    It's nice from Microsoft to offer things like the Client Framework for anybody who doesn't need the complete framework to run an application. But for about an hour I a searching the web for a redistributable version of this package. I can't find anything. It looks like Client Framework is only possible for Click-Once deployment or a bootstrapper who will download the framework. These are no options for me. On this page http://www.microsoft.com/downloads/details.aspx?familyid=992cffcb-f8ce-41d9-8bd6-31f3e216285c&displaylang=en I found a package that will contain both "The download package contains the .NET Framework Client Profile and the full .NET Framework 3.5 Service Pack 1." But again this is not what I need and it's even bigger that the singleFramework. Is there anything like the .NET 3.5 Client Framework redistributable ?

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  • Flex Framework vs. Micro-Architecture

    - by droboZ
    I'm in the process of choosing a framework for my flex development, and one of the questions that was asked about a framework was "is this a framework or a micro-architecture"? Can someone clarify what's the difference? What exactly is a framework, and when can we start calling what we have a framework? I work with FlexBuilder3 (now called FlashBuilder4) and have a lot of standard things that I do for almost all projects, and components that I created for easy re-use. Some are very very small, but the benefit of a 1-liner has been immense for me instead of repeating the code over and over. So in the framework/micro-architecture scheme, can I say that these are my internal in-house framework or are they part of a micro-architecture? Trying to understand this topic better.

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  • LINQ-like or SQL-like DSL for end-users to run queries to select (not modify) data?

    - by Mark Rushakoff
    For a utility I'm working on, the client would like to be able to generate graphic reports on the data that has been collected. I can already generate a couple canned graphs (using ZedGraph, which is a very nice library); however, the utility would be much more flexible if the graphs were more programmable or configurable by the end-user. TLDR version I want users to be able to use something like SQL to safely extract and select data from a List of objects that I provide and can describe. What free tools or libraries will help me accomplish this? Full version I've given thought to using IronPython, IronRuby, and LuaInterface, but frankly they're all a bit overpowered for what I want to do. My classes are fairly simple, along the lines of: class Person: string Name; int HeightInCm; DateTime BirthDate; Weight[] WeighIns; class Weight: int WeightInKg; DateTime Date; Person Owner; (exact classes have been changed to protect the innocent). To come up with the data for the graph, the user will choose whether it's a bar graph, scatter plot, etc., and then to actually obtain the data, I would like to obtain some kind of List from the user simply entering something SQL-ish along the lines of SELECT Name, AVG(WeighIns) FROM People SELECT WeightInKg, Owner.HeightInCm FROM Weights And as a bonus, it would be nice if you could actually do operations as well: SELECT WeightInKg, (Date - Owner.BirthDate) AS Age FROM Weights The DSL doesn't have to be compliant SQL in any way; it doesn't even have to resemble SQL, but I can't think of a more efficient descriptive language for the task. I'm fine filling in blanks; I don't expect a library to do everything for me. What I would expect to exist (but haven't been able to find in any way, shape, or form) is something like Fluent NHibernate (which I am already using in the project) where I can declare a mapping, something like var personRequest = Request<Person>(); personRequest.Item("Name", (p => p.Name)); personRequest.Item("HeightInCm", (p => p.HeightInCm)); personRequest.Item("HeightInInches", (p => p.HeightInCm * CM_TO_INCHES)); // ... var weightRequest = Request<Weight>(); weightRequest.Item("Owner", (w => w.Owner), personRequest); // Indicate a chain to personRequest // ... var people = Table<Person>("People", GetPeopleFromDatabase()); var weights = Table<Weight>("Weights", GetWeightsFromDatabase()); // ... TryRunQuery(userInputQuery); LINQ is so close to what I want to do, but AFAIK there's no way to sandbox it. I don't want to expose any unnecessary functionality to the end user; meaning I don't want the user to be able to send in and process: from p in people select (p => { System.IO.File.Delete("C:\\something\\important"); return p.Name }) So does anyone know of any free .NET libraries that allow something like what I've described above? Or is there some way to sandbox LINQ? cs-script is close too, but it doesn't seem to offer sandboxing yet either. I'd be hesitant to expose the NHibernate interface either, as the user should have a read-only view of the data at this point in the usage. I'm using C# 3.5, and pure .NET solutions would be preferred. The bottom line is that I'm really trying to avoid writing my own parser for a subset of SQL that would only apply to this single project.

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  • Framework vs. Micro-Architecture, which is mine

    - by droboZ
    I'm in the process of choosing a framework for my flex development, and one of the questions that was asked about a framework was "is this a framework or a micro-architecture"? Can someone clarify what's the difference? What exactly is a framework, and when can we start calling what we have a framework? I work with FlexBuilder3 (now called FlashBuilder4) and have a lot of standard things that I do for almost all projects, and components that I created for easy re-use. Some are very very small, but the benefit of a 1-liner has been immense for me instead of repeating the code over and over. So in the framework/micro-architecture scheme, can I say that these are my internal in-house framework or are they part of a micro-architecture? Trying to understand this topic better.

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  • Talks Submitted for Ann Arbor Day of .NET 2010

    - by PSteele
    Just submitted my session abstracts for Ann Arbor's Day of .NET 2010.   Getting up to speed with .NET 3.5 -- Just in time for 4.0! Yes, C# 4.0 is just around the corner.  But if you haven't had the chance to use C# 3.5 extensively, this session will start from the ground up with the new features of 3.5.  We'll assume everyone is coming from C# 2.0.  This session will show you the details of extension methods, partial methods and more.  We'll also show you how LINQ -- Language Integrated Query -- can help decrease your development time and increase your code's readability.  If time permits, we'll look at some .NET 4.0 features, but the goal is to get you up to speed on .NET 3.5.   Go Ahead and Mock Me! When testing specific parts of your application, there can be a lot of external dependencies required to make your tests work.  Writing fake or mock objects that act as stand-ins for the real dependencies can waste a lot of time.  This is where mocking frameworks come in.  In this session, Patrick Steele will introduce you to Rhino Mocks, a popular mocking framework for .NET.  You'll see how a mocking framework can make writing unit tests easier and leads to less brittle unit tests.   Inversion of Control: Who's got control and why is it being inverted? No doubt you've heard of "Inversion of Control".  If not, maybe you've heard the term "Dependency Injection"?  The two usually go hand-in-hand.  Inversion of Control (IoC) along with Dependency Injection (DI) helps simplify the connections and lifetime of all of the dependent objects in the software you write.  In this session, Patrick Steele will introduce you to the concepts of IoC and DI and will show you how to use a popular IoC container (Castle Windsor) to help simplify the way you build software and how your objects interact with each other. If you're interested in speaking, hurry up and get your submissions in!  The deadline is Monday, April 5th! Technorati Tags: .NET,Ann Arbor,Day of .NET

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