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  • ASP.NET RadioButton messing with the name (groupname)

    - by Hojou
    I got a templated control (a repeater) listing some text and other markup. Each item has a radiobutton associated with it, making it possible for the user to select ONE of the items created by the repeater. The repeater writes the radiobutton setting its id and name generated with the default asp.net naming convention making each radiobutton a full 'group'. This means all radiobuttons are independant on each other, which again unfortunately means i can select all radiobuttons at the same time. The radiobutton has the clever attribute 'groupname' used to set a common name so they get grouped together and thus should be dependant (so i can only select one at a time). The problem is - this doesn't work - the repeater makes sure the id and thus the name (which controls the grouping) are different. Since i use a repeater (could have been a listview or any other templated databound control) i can't use the RadioButtonList. So where does that leave me? I know i've had this problem before and solved it. I know almost every asp.net programmer must have had it too, so why can't i google and find a solid solution to the problem? I came across solutions to enforce the grouping by javascript (ugly!) or even to handle the radiobuttons as non-server controls, forcing me to do a Request.Form[name] to read the status. I also tried experimenting with overriding the name attribute on the PreRender event - unfortunately the owning page and masterpage again overrides this name to reflect the full id/name so i end up with the same wrong result. If you have no better solution than i posted, you are still very welcome to post your thoughts - atleast i'll know that my friend 'jack' is right about how messed up 'asp.net' is sometimes ;)

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  • nServiceBus - No all commands being received by handler

    - by SimonB
    In a test project based of the nServiceBus pub/sub sample, I've replace the bus.publish with bus.send in the server. The server sends 50 messages with a 1sec wait after each 5 (ie 10 burst of 5 messages). The client does not get all the messages. The soln has 3 projects - Server, Client, and common messages. The server and client are hosted via the nServiceBus generic host. Only a single bus is defined. Both client and server are configured to use StructureMap builder and BinarySerialisation. Server Endpoint: public class EndPointConfig : AsA_Publisher, IConfigureThisEndpoint, IWantCustomInitialization { public void Init() { NServiceBus.Configure.With() .StructureMapBuilder() .BinarySerializer(); } } Server Code : for (var nextId = 1; nextId <= 50; nextId++) { Console.WriteLine("Sending {0}", nextId); IDataMsg msg = new DataMsg { Id = nextId, Body = string.Format("Batch Msg #{0}", nextId) }; _bus.SendLocal(msg); Console.WriteLine(" ...sent {0}", nextId); if ((nextId % 5) == 0) Thread.Sleep(1000); } Client Endpoint: public class EndPointConfig : AsA_Client, IConfigureThisEndpoint, IWantCustomInitialization { public void Init() { NServiceBus.Configure.With() .StructureMapBuilder() .BinarySerializer(); } } Client Clode: public class DataMsgHandler : IMessageHandler<IDataMsg> { public void Handle(IDataMsg msg) { Console.WriteLine("DataMsgHandler.Handle({0}, {1}) - ({2})", msg.Id, msg.Body, Thread.CurrentThread.ManagedThreadId); } } Client and Server App.Config: <MsmqTransportConfig InputQueue="nsbt02a" ErrorQueue="error" NumberOfWorkerThreads="1" MaxRetries="5" /> <UnicastBusConfig DistributorControlAddress="" DistributorDataAddress=""> <MessageEndpointMappings> <add Messages="Test02.Messages" Endpoint="nsbt02a" /> </MessageEndpointMappings> </UnicastBusConfig> All run via VisualStudio 2008. All 50 messages are sent - but after the 1st or 2nd batch. only 1 msg per batch is sent? Any ideas? I'm assuming config or misuse but ....?

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  • algorithm || method to write prog

    - by fatai
    I am one of the computer science student. My wonder is everyone solve problem with different or same method, but actually I dont know whether they use method or I dont know whether there are such common method to approach problem. All teacher give us problem which in simple form sometimes, but they dont introduce any approach or method(s) so that we can first choose method then apply that one to problem , afterward find solution then write code. I have found one method when I failed the course, More accurately, When I counter problem in language , I will get more paper and then ; first, input/ output step ; my prog will take this / these there argument(s) and return namely X , ex : in c, input length is not known and at same type , so I must use pointer desired output is in form of package , so use structure second, execution part ; in that step , I am writing all step which are goes to final output ex : in python ; 1.) [ + , [- , 4 , [ * , 1 , 2 ]], 5] 2.) [ + , [- , 4 , 2 ],5 ] 3.) [ + , 2 , 5] 4.) 7 ==> return 7 third, I will write test code ex : in c++ input : append 3 4 5 6 vector_x remove 0 1 desired output vector_x holds : 5 6 But now, I wonder other method ; used to construct class :::: for c++ , python, java used to communicate classes / computers used for solving embedded system problem ::::: for c Why I wonder , because I learn if you dont costruct algorithm on paper, you may achieve your goal. Like no money no lunch , I can say no algorithm no prog therefore , feel free when you write your own method , a way which is introduced by someone else but you are using and you find it is so efficient

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  • deepcopy and python - tips to avoid using it?

    - by blackkettle
    Hi, I have a very simple python routine that involves cycling through a list of roughly 20,000 latitude,longitude coordinates and calculating the distance of each point to a reference point. def compute_nearest_points( lat, lon, nPoints=5 ): """Find the nearest N points, given the input coordinates.""" points = session.query(PointIndex).all() oldNearest = [] newNearest = [] for n in xrange(nPoints): oldNearest.append(PointDistance(None,None,None,99999.0,99999.0)) newNearest.append(obj2) #This is almost certainly an inappropriate use of deepcopy # but how SHOULD I be doing this?!?! for point in points: distance = compute_spherical_law_of_cosines( lat, lon, point.avg_lat, point.avg_lon ) k = 0 for p in oldNearest: if distance < p.distance: newNearest[k] = PointDistance( point.point, point.kana, point.english, point.avg_lat, point.avg_lon, distance=distance ) break else: newNearest[k] = deepcopy(oldNearest[k]) k += 1 for j in range(k,nPoints-1): newNearest[j+1] = deepcopy(oldNearest[j]) oldNearest = deepcopy(newNearest) #We're done, now print the result for point in oldNearest: print point.station, point.english, point.distance return I initially wrote this in C, using the exact same approach, and it works fine there, and is basically instantaneous for nPoints<=100. So I decided to port it to python because I wanted to use SqlAlchemy to do some other stuff. I first ported it without the deepcopy statements that now pepper the method, and this caused the results to be 'odd', or partially incorrect, because some of the points were just getting copied as references(I guess? I think?) -- but it was still pretty nearly as fast as the C version. Now with the deepcopy calls added, the routine does it's job correctly, but it has incurred an extreme performance penalty, and now takes several seconds to do the same job. This seems like a pretty common job, but I'm clearly not doing it the pythonic way. How should I be doing this so that I still get the correct results but don't have to include deepcopy everywhere?

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  • What is the best software design to use in this scenario

    - by domdefelice
    I need to generate HTML snippets using jQuery. The creation of those snippets depends on some data. The data is stored server-side, in session (where PHP is used). At the moment I achieved this - retrieving the data from the server via AJAX in form of JSON - and building the snippets via specific javascript functions that read those data The problem is that the complexity of the data is getting bigger and hence the serialization into JSON is getting even more difficult since I can't do it automatically. I can't do it automatically because some information are sensible so I generate a "stripped" version to send to the client. I know it is difficult to understand without any code to read, but I am hoping this is a common scenario and would be glad for any tip, suggestion or even design-pattern you can give me. Should I store both a complete and a stripped data on the server and then use some library to automatically generate the JSON from the stripped data? But this also means I have to get the two data synchronized. Or maybe I could move the logic server-side, this way avoiding sending the data. But this means sending javascript code (since I rely on jQuery). Maybe not a good idea. Feel free to ask me more details if this is not clear. Thank you for any help

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  • Hibernate Auto-Increment Setup

    - by dharga
    How do I define an entity for the following table. I've got something that isn't working and I just want to see what I'm supposed to do. USE [BAMPI_TP_dev] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO SET ANSI_PADDING ON GO CREATE TABLE [dbo].[MemberSelectedOptions]( [OptionId] [int] NOT NULL, [SeqNo] [smallint] IDENTITY(1,1) NOT NULL, [OptionStatusCd] [char](1) NULL ) ON [PRIMARY] GO SET ANSI_PADDING OFF This is what I have already that isn't working. @Entity @Table(schema="dbo", name="MemberSelectedOptions") public class MemberSelectedOption extends BampiEntity implements Serializable { @Embeddable public static class MSOPK implements Serializable { private static final long serialVersionUID = 1L; @Column(name="OptionId") int optionId; @GeneratedValue(strategy=GenerationType.IDENTITY) @Column(name="SeqNo", unique=true, nullable=false) BigDecimal seqNo; //Getters and setters here... } private static final long serialVersionUID = 1L; @EmbeddedId MSOPK pk = new MSOPK(); @Column(name="OptionStatusCd") String optionStatusCd; //More Getters and setters here... } I get the following ST. [5/25/10 15:49:40:221 EDT] 0000003d JDBCException E org.slf4j.impl.JCLLoggerAdapter error Cannot insert explicit value for identity column in table 'MemberSelectedOptions' when IDENTITY_INSERT is set to OFF. [5/25/10 15:49:40:221 EDT] 0000003d AbstractFlush E org.slf4j.impl.JCLLoggerAdapter error Could not synchronize database state with session org.hibernate.exception.SQLGrammarException: could not insert: [com.bob.proj.ws.model.MemberSelectedOption] at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:90) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66) at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2285) at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2678) at org.hibernate.action.EntityInsertAction.execute(EntityInsertAction.java:79) at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:279) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:263) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:167) at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321) at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:50) at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1028) at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:366) at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:137) at com.bcbst.bamp.ws.dao.MemberSelectedOptionDAOImpl.saveMemberSelectedOption(MemberSelectedOptionDAOImpl.java:143) at com.bcbst.bamp.ws.common.AlertReminder.saveMemberSelectedOptions(AlertReminder.java:76) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)

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  • Test Views in ASP.NET MVC2 (ala RSpec)

    - by Dmitriy Nagirnyak
    Hi, I am really missing heavily the ability to test Views independently of controllers. The way RSpec does it. What I want to do is to perform assertions on the rendered view (where no controller is involved!). In order to do so I should provide required Model, ViewData and maybe some details from HttpContextBase (when will we get rid of HttpContext!). So far I have not found anything that allows doing it. Also it might heavily depend on the ViewEngine being used. List of things that views might contain are: Partial views (may be nested deeply). Master pages (or similar in other view engines). Html helpers generating links and other elements. Generally almost anything in a range of common sense :) . Also please note that I am not talking about client-side testing and thus Selenium is just not related to it at all. It is just plain .NET testing. So are there any options to actually do the testing of views? Thanks, Dmitriy.

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  • Silverlight and WCF Ria Services

    - by Flex_Addicted
    Hi guys, I've created a new Silverlight 3 Business Application with VS 2008. The creation has completed correctly. When I try to open the xaml, it opens but in meanwhile this error is shown: Failed to load metadata assembly System.Windows.Controls.Data.Input.Design, Version=2.0.5.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35. Exception message: Unable to load one or more of the requested types. Retrieve the LoaderExceptions property for more information.. Stack Trace: at System.Reflection.Module._GetTypesInternal(StackCrawlMark& stackMark) at System.Reflection.Assembly.GetTypes() at MS.Internal.Package.MetadataLoader.RegisterDesignTimeMetadata(Assembly assembly, LogCallback logger)An exception of type ArgumentNullException was caught when calling IRegisterMetadata on type System.Windows.Controls.Data.Input.VisualStudio.Design.MetadataRegistration. Exception Message: Value cannot be null. Parameter name: type. Stack Trace: at Microsoft.Windows.Design.Metadata.AttributeTableBuilder.AddCallback(Type type, AttributeCallback callback) at System.Windows.Controls.Data.Input.VisualStudio.Design.MetadataRegistration.AddAttributes(AttributeTableBuilder builder) at System.Windows.Controls.Design.Common.MetadataRegistrationBase.BuildAttributeTable() at System.Windows.Controls.Data.Input.VisualStudio.Design.MetadataRegistration.Register() at MS.Internal.Package.MetadataLoader.RegisterDesignTimeMetadata(Assembly assembly, LogCallback logger)Failed to load metadata assembly System.Windows.Controls.Design, Version=2.0.5.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35. Exception message: Unable to load one or more of the requested types. Retrieve the LoaderExceptions property for more information.. Stack Trace: at System.Reflection.Module._GetTypesInternal(StackCrawlMark& stackMark) at System.Reflection.Assembly.GetTypes() at MS.Internal.Package.MetadataLoader.RegisterDesignTimeMetadata(Assembly assembly, LogCallback logger)Failed to load metadata assembly System.Windows.Controls.Navigation.Design, Version=2.0.5.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35. Exception message: Unable to load one or more of the requested types. Retrieve the LoaderExceptions property for more information.. Stack Trace: at System.Reflection.Module._GetTypesInternal(StackCrawlMark& stackMark) at System.Reflection.Assembly.GetTypes() at MS.Internal.Package.MetadataLoader.RegisterDesignTimeMetadata(Assembly assembly, LogCallback logger) Why? Any solutions? Thank you in advance.

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  • maven-release-plugin: Perform fails with 'working directory "...workspace\target\checkout\workspace"

    - by Ed
    Hi, I have maven project that fails when release:perform is called, though release;prepare works as expected. I have found the bug report (below) which certainly seems to resemble the issue I have but not entirely sure I understand the problem: MRELEASE516 The last few lines of output I get: [INFO] Executing: cmd.exe /X /C "p4 -d E:\hudson\jobs\myHudsonJob\workspace\target\checkout -p 10.20.0.38:1666 client -d myProjectWorkspace-MavenSCM-E:\hudson\jobs\myHudsonJob\workspace\target\checkout" [INFO] Executing goals 'deploy'... [WARNING] Base directory is a file. Using base directory as POM location. [WARNING] Maven will be executed in interactive mode, but no input stream has been configured for this MavenInvoker instance. [INFO] ------------------------------------------------------------------------ [ERROR] BUILD ERROR [INFO] ------------------------------------------------------------------------ [INFO] Error executing Maven. Working directory "E:\hudson\jobs\myHudsonJob\workspace\target\checkout\workspace" does not exist! From reading the bug report the possible cause of the error is related to my modules' structure, I've tried to outline it below: /workspace | |+ pom.xml (root pom whose parent is the build pom, | calling release:perform on this pom) | [Modules: moduleA and moduleB] | |- moduleA |+ pom.xml (parent is also build pom) |+ build/pom.xml (the build pom - no custom parent) |- moduleB |+ pom.xml (parent is build pom) It seems that the root pom should be in some common directory inside 'workspace' from the error but tried that and doesn't work, nor make sense as to why I need it. What does the warning Base directory is a file want me to do instead?! It then figures that the base directory is workspace which then means the working directory is not found...any ideas? Thanks in advance.

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  • database schema eligible for delta synchronization

    - by WilliamLou
    it's a question for discussion only. Right now, I need to re-design a mysql database table. Basically, this table contains all the contract records I synchronized from another database. The contract record can be modified, deleted or users can add new contract records via GUI interface. At this stage, the table structure is exactly the same as the Contract info (column: serial number, expiry date etc.). In that case, I can only synchronize the whole table (delete all old records, replace with new ones). If I want to delta(only synchronize with modified, new, deleted records) synchronize the table, how should I change the database schema? here is the method I come up with, but I need your suggestions because I think it's a common scenario in database applications. 1)introduce a sequence number concept/column: for each sequence, mark the new added records, modified records, deleted records with this sequence number. By recording the last synchronized sequence number, only pass those records with higher sequence number; 2) because deleted contracts can be added back, and the original table has primary key constraints, should I create another table for those deleted records? or add a flag column to indicate if this contract has been deleted? I hope I explain my question clearly. Anyway, if you know any articles or your own suggestions about this, please let me know. Thanks!

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  • Free tools/libraries to compare tables with filtering in different databases and visualize/sync diff

    - by MicMit
    I am building certain GUI in C# for a content manager and looking for the tools or code snippets or open libraries ( code ideally in C# ) which allow me the following : 1. For table A in database X (test ) and table A in database Y (production) and for a simple filter ( e.g. listname = "XYZ" ) I need to show additions/deletions/updates in some way. which might be side-by-side or just html report 2 record added html table with some fields 2 record deleted html table with some fields Considering that this task is very common, I guess, certain components should exist ? Components either return some collections from parameters given for further visualizing or just produce reports mentioned above. 2. I need to push changes for the filter I mentioned in 1 and update table in production database for this filter only ( ie for the particular list approved by content person). Again probably there are certain SQL code generators - components in addition to diffs or standalone. 3. The key thing tools/libraries - should be suitable for integration with the existing application in C#.

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  • The algorithm used to generate recommendations in Google News?

    - by Siddhant
    Hi everyone. I'm study recommendation engines, and I went through the paper that defines how Google News generates recommendations to users for news items which might be of their interest, based on collaborative filtering. One interesting technique that they mention is Minhashing. I went through what it does, but I'm pretty sure that what I have is a fuzzy idea and there is a strong chance that I'm wrong. The following is what I could make out of it :- Collect a set of all news items. Define a hash function for a user. This hash function returns the index of the first item from the news items which this user viewed, in the list of all news items. Collect, say "n" number of such values, and represent a user with this list of values. Based on the similarity count between these lists, we can calculate the similarity between users as the number of common items. This reduces the number of comparisons a lot. Based on these similarity measures, group users into different clusters. This is just what I think it might be. In Step 2, instead of defining a constant hash function, it might be possible that we vary the hash function in a way that it returns the index of a different element. So one hash function could return the index of the first element from the user's list, another hash function could return the index of the second element from the user's list, and so on. So the nature of the hash function satisfying the minwise independent permutations condition, this does sound like a possible approach. Could anyone please confirm if what I think is correct? Or the minhashing portion of Google News Recommendations, functions in some other way? I'm new to internal implementations of recommendations. Any help is appreciated a lot. Thanks!

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  • How close can I get C# to the performance of C++ for small intensive tasks?

    - by SLC
    I was thinking about the speed difference of C++ to C# being mostly about C# compiling to byte-code that is taken in by the JIT compiler (is that correct?) and all the checks C# does. I notice that it is possible to turn a lot of these functions off, both in the compile options, and possibly through using the unsafe keyword as unsafe code is not verifiable by the common language runtime. Therefore if you were to write a simple console application in both languages, that flipped an imaginary coin an infinite number of times and displayed the results to the screen every 10,000 or so iterations, how much speed difference would there be? I chose this because it's a very simple program. I'd like to test this but I don't know C++ or have the tools to compile it. This is my C# version though: static void Main(string[] args) { unsafe { Random rnd = new Random(); int heads = 0, tails = 0; while (true) { if (rnd.NextDouble() > 0.5) heads++; else tails++; if ((heads + tails) % 1000000 == 0) Console.WriteLine("Heads: {0} Tails: {1}", heads, tails); } } } Is the difference enough to warrant deliberately compiling sections of code "unsafe" or into DLLs that do not have some of the compile options like overflow checking enabled? Or does it go the other way, where it would be beneficial to compile sections in C++? I'm sure interop speed comes into play too then. To avoid subjectivity, I reiterate the specific parts of this question as: Does C# have a performance boost from using unsafe code? Do the compile options such as disabling overflow checking boost performance, and do they affect unsafe code? Would the program above be faster in C++ or negligably different? Is it worth compiling long intensive number-crunching tasks in a language such as C++ or using /unsafe for a bonus? Less subjectively, could I complete an intensive operation faster by doing this?

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  • Classification: Dealing with Abstain/Rejected Class

    - by abner.ayala
    I am asking for your input and/help on a classification problem. If anyone have any references that I can read to help me solve my problem even better. I have a classification problem of four discrete and very well separated classes. However my input is continuous and has a high frequency (50Hz), since its a real-time problem. The circles represent the clusters of the classes, the blue line the decision boundary and Class 5 equals the (neutral/resting do nothing class). This class is the rejected class. However the problem is that when I move from one class to the other I activate a lot of false positives in the transition movements, since the movement is clearly non-linear. For example, every time I move from class 5 (neutral class) to 1 I first see a lot of 3's before getting to the 1 class. Ideally, I will want my decision boundary to look like the one in the picture below where the rejected class is Class =5. Has a higher decision boundary than the others classes to avoid misclassification during transition. I am currently implementing my algorithm in Matlab using naive bayes, kNN, and SVMs optimized algorithms using Matlab. Question: What is the best/common way to handle abstain/rejected classes classes? Should I use (fuzzy logic, loss function, should I include resting cluster in the training)?

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  • "Pattern matching" of algebraic type data constructors

    - by jetxee
    Let's consider a data type with many constructors: data T = Alpha Int | Beta Int | Gamma Int Int | Delta Int I want to write a function to check if two values are produced with the same constructor: sameK (Alpha _) (Alpha _) = True sameK (Beta _) (Beta _) = True sameK (Gamma _ _) (Gamma _ _) = True sameK _ _ = False Maintaining sameK is not much fun, it is potentially buggy. For example, when new constructors are added to T, it's easy to forget to update sameK. I omitted one line to give an example: -- it’s easy to forget: -- sameK (Delta _) (Delta _) = True The question is how to avoid boilerplate in sameK? Or how to make sure it checks for all T constructors? The workaround I found is to use separate data types for each of the constructors, deriving Data.Typeable, and declaring a common type class, but I don't like this solution, because it is much less readable and otherwise just a simple algebraic type works for me: {-# LANGUAGE DeriveDataTypeable #-} import Data.Typeable class Tlike t where value :: t -> t value = id data Alpha = Alpha Int deriving Typeable data Beta = Beta Int deriving Typeable data Gamma = Gamma Int Int deriving Typeable data Delta = Delta Int deriving Typeable instance Tlike Alpha instance Tlike Beta instance Tlike Gamma instance Tlike Delta sameK :: (Tlike t, Typeable t, Tlike t', Typeable t') => t -> t' -> Bool sameK a b = typeOf a == typeOf b

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  • Free tools/libraries to compare tables with filtering for SQL Server 2008 and visualize/sync diffs t

    - by MicMit
    I am building certain GUI in C# for a content manager and looking for the tools or code snippets or open libraries ( code ideally in C# ) which allow me the following : 1. For table A in database X (test ) and table A in database Y (production) and for a simple filter ( e.g. listname = "XYZ" ) I need to show additions/deletions/updates in some way. which might be side-by-side or just html report 2 record added html table with some fields 2 record deleted html table with some fields Considering that this task is very common, I guess, certain components should exist ? Components either return some collections from parameters given for further visualizing or just produce reports mentioned above. 2. I need to push changes for the filter I mentioned in 1 and update table in production database for this filter only ( ie for the particular list approved by content person). Again probably there are certain SQL code generators - components in addition to diffs or standalone. 3. The key thing tools/libraries - should be suitable for integration with the existing application in C#.

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  • Parsing basic math equations for children's educational software?

    - by Simucal
    Inspired by a recent TED talk, I want to write a small piece of educational software. The researcher created little miniature computers in the shape of blocks called "Siftables". [David Merril, inventor - with Siftables in the background.] There were many applications he used the blocks in but my favorite was when each block was a number or basic operation symbol. You could then re-arrange the blocks of numbers or operation symbols in a line, and it would display an answer on another siftable block. So, I've decided I wanted to implemented a software version of "Math Siftables" on a limited scale as my final project for a CS course I'm taking. What is the generally accepted way for parsing and interpreting a string of math expressions, and if they are valid, perform the operation? Is this a case where I should implement a full parser/lexer? I would imagine interpreting basic math expressions would be a semi-common problem in computer science so I'm looking for the right way to approach this. For example, if my Math Siftable blocks where arranged like: [1] [+] [2] This would be a valid sequence and I would perform the necessary operation to arrive at "3". However, if the child were to drag several operation blocks together such as: [2] [\] [\] [5] It would obviously be invalid. Ultimately, I want to be able to parse and interpret any number of chains of operations with the blocks that the user can drag together. Can anyone explain to me or point me to resources for parsing basic math expressions? I'd prefer as much of a language agnostic answer as possible.

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  • Table valued function only returns CLR error

    - by Anthony
    I have read-only access to a database that was set up for a third-party, closed-source app. Once group of (hopefully) useful table functions only returns the error: Failed to initialize the Common Language Runtime (CLR) v2.0.50727 with HRESULT 0x80131522. You need to restart SQL server to use CLR integration features. (severity 16) But in theory, the third-party app should be able to use the function (either directly or indirectly), so I'm convinced I'm not setting things up right. I'm very new to SQL Server, so I could be missing something obvious. Or I could be missing something really slight, I have no idea. Here is an example of a query that returns the above error: SELECT * FROM dbo.UncompressDataDateRange(4,'Apr 24 2010 12:00AM','Apr 30 2010 12:00AM') Where the function takes three parameters: The Data Set (int) -- basically the data has 6 classifications, and the giant table this should be pulling from has a column to indicate which is which. startDate (smalldatetime) endDate (smalldatetime) There are other, similar functions that expand on the same idea, all returning the same error. Quick Note: I'm not sure if this is relevant, but I was able to connect to the database via SQL Studio (but without the privs to script the functions as code), and a checked the dependency for the above sample function. It turns out that it is a dependent of a view that I have gotten to work, and that view is dependent of the larger, much-hairier data-table. This makes me think I should somehow be pointing the function at the results of the view, but I'm not seeing any documentation that shows how that is done.

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  • How to make a mapped field inherited from a superclass transient in JPA?

    - by Russ Hayward
    I have a legacy schema that cannot be changed. I am using a base class for the common features and it contains an embedded object. There is a field that is normally mapped in the embedded object that needs to be in the persistence id for only one (of many) subclasses. I have made a new id class that includes it but then I get the error that the field is mapped twice. Here is some example code that is much simplified to maintain the sanity of the reader: @MappedSuperclass class BaseClass { @Embedded private Data data; } @Entity class SubClass extends BaseClass { @EmbeddedId private SubClassId id; } @Embeddable class Data { private int location; private String name; } @Embeddable class SubClassId { private int thingy; private int location; } I have tried @AttributeOverride but I can only get it to rename the field. I have tried to set it to updatable = false, insertable = false but this did not seem to work when used in the @AttributeOverride annotation. See answer below for the solution to this issue. I realise I could change the base class but I really do not want to split up the embedded object to separate the shared field as it would make the surrounding code more complex and require some ugly wrapping code. I could also redesign the whole system for this corner case but I would really rather not. I am using Hibernate as my JPA provider.

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  • Static variable for communication among like-typed objects

    - by Dan Ray
    I have a method that asynchronously downloads images. If the images are related to an array of objects (a common use-case in the app I'm building), I want to cache them. The idea is, I pass in an index number (based on the indexPath.row of the table I'm making by way through), and I stash the image in a static NSMutableArray, keyed on the row of the table I'm dealing with. Thusly: @implementation ImageDownloader ... @synthesize cacheIndex; static NSMutableArray *imageCache; -(void)startDownloadWithImageView:(UIImageView *)imageView andImageURL:(NSURL *)url withCacheIndex:(NSInteger)index { self.theImageView = imageView; self.cacheIndex = index; NSLog(@"Called to download %@ for imageview %@", url, self.theImageView); if ([imageCache objectAtIndex:index]) { NSLog(@"We have this image cached--using that instead"); self.theImageView.image = [imageCache objectAtIndex:index]; return; } self.activeDownload = [NSMutableData data]; NSURLConnection *conn = [[NSURLConnection alloc] initWithRequest:[NSURLRequest requestWithURL:url] delegate:self]; self.imageConnection = conn; [conn release]; } //build up the incoming data in self.activeDownload with calls to didReceiveData... - (void)connectionDidFinishLoading:(NSURLConnection *)connection { NSLog(@"Finished downloading."); UIImage *image = [[UIImage alloc] initWithData:self.activeDownload]; self.theImageView.image = image; NSLog(@"Caching %@ for %d", self.theImageView.image, self.cacheIndex); [imageCache insertObject:image atIndex:self.cacheIndex]; NSLog(@"Cache now has %d items", [imageCache count]); [image release]; } My index is getting through okay, I can see that by my NSLog output. But even after my insertObject: atIndex: call, [imageCache count] never leaves zero. This is my first foray into static variables, so I presume I'm doing something wrong. (The above code is heavily pruned to show only the main thing of what's going on, so bear that in mind as you look at it.)

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  • Most unintuitive behaviour in the .Net framework?

    - by BlueRaja
    Intended behavior is often another phrase for bug-which-we-knew-about-when-we-wrote-it, but-we-wrote-it-anyways. Because it was "intended" (or perhaps it is now too late or too difficult), many of these extremely-unintuitive bugs never get fixed. For instance, consider the following code (C#): TextInfo textInfo = Thread.CurrentThread.CurrentCulture.TextInfo; textInfo.ToTitleCase("hello world!"); //Returns "Hello World!" textInfo.ToTitleCase("hElLo WoRld!"); //Returns "Hello World!" textInfo.ToTitleCase("Hello World!"); //Returns "Hello World!" What would you expect textInfo.ToTitleCase("HELLO WORLD!"); to return? In fact, it returns "HELLO WORLD!". This was well-documented "intended behavior," but, in my eyes, is extremely unintuitive, and therefore a bug. What is some other unintuitive behavior like this in this in the .Net framework? Bonus points if you can provide a fix that does not break backwards-compatibility. Remember! Always keep these two simple rules in mind when designing an API (or anything else): Make the common case the default, and Keep It Simple, Stupid!

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  • Why put a DAO layer over a persistence layer (like JDO or Hibernate)

    - by Todd Owen
    Data Access Objects (DAOs) are a common design pattern, and recommended by Sun. But the earliest examples of Java DAOs interacted directly with relational databases -- they were, in essence, doing object-relational mapping (ORM). Nowadays, I see DAOs on top of mature ORM frameworks like JDO and Hibernate, and I wonder if that is really a good idea. I am developing a web service using JDO as the persistence layer, and am considering whether or not to introduce DAOs. I foresee a problem when dealing with a particular class which contains a map of other objects: public class Book { // Book description in various languages, indexed by ISO language codes private Map<String,BookDescription> descriptions; } JDO is clever enough to map this to a foreign key constraint between the "BOOKS" and "BOOKDESCRIPTIONS" tables. It transparently loads the BookDescription objects (using lazy loading, I believe), and persists them when the Book object is persisted. If I was to introduce a "data access layer" and write a class like BookDao, and encapsulate all the JDO code within this, then wouldn't this JDO's transparent loading of the child objects be circumventing the data access layer? For consistency, shouldn't all the BookDescription objects be loaded and persisted via some BookDescriptionDao object (or BookDao.loadDescription method)? Yet refactoring in that way would make manipulating the model needlessly complicated. So my question is, what's wrong with calling JDO (or Hibernate, or whatever ORM you fancy) directly in the business layer? Its syntax is already quite concise, and it is datastore-agnostic. What is the advantage, if any, of encapsulating it in Data Access Objects?

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  • notify listener inside or outside inner synchronization

    - by Jary Zeels
    Hello all, I am struggling with a decision. I am writing a thread-safe library/API. Listeners can be registered, so the client is notified when something interesting happens. Which of the two implementations is most common? class MyModule { protected Listener listener; protected void somethingHappens() { synchronized(this) { ... do useful stuff ... listener.notify(); } } } or class MyModule { protected Listener listener; protected void somethingHappens() { Listener l = null; synchronized(this) { ... do useful stuff ... l = listener; } l.notify(); } } In the first implementation, the listener is notified inside the synchronization. In the second implementation, this is done outside the synchronization. I feel that the second one is advised, as it makes less room for potential deadlocks. But I am having trouble to convince myself. A downside of the second imlementation is that the client might receive 'incorrect' notifications, which happens if it accessed the module prior to the l.notify() statement. thanks a lot

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  • Can I use the auto-generated Linq-to-SQL entity classes in 'disconnected' mode?

    - by Gary McGill
    Suppose I have an automatically-generated Employee class based on the Employees table in my database. Now suppose that I want to pass employee data to a ShowAges method that will print out name & age for a list of employees. I'll retrieve the data for a given set of employees via a linq query, which will return me a set of Employee instances. I can then pass the Employee instances to the ShowAges method, which can access the Name & Age fields to get the data it needs. However, because my Employees table has relationships with various other tables in my database, my Employee class also has a Department field, a Manager field, etc. that provide access to related records in those other tables. If the ShowAges method were to invoke any of those methods, this would cause lots more data to be fetched from the database, on-demand. I want to be sure that the ShowAges method only uses the data I have already fetched for it, but I really don't want to have to go to the trouble of defining a new class which replicates the Employee class but has fewer methods. (In my real-world scenario, the class would have to be considerably more complex than the Employee class described here; it would have several 'joined' classes that do need to be populated, and others that don't). Is there a way to 'switch off' or 'disconnect' the Employees instances so that an attempt to access any property or related object that's not already populated will raise an exception? If not, then I assume that since this must be a common requirement, there might be an already-established pattern for doing this sort of thing?

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  • ASP.NET MVC static-asset aides/practices

    - by shannon
    I want to keep assets that are only used by one view in a view-specific folder, so my Search.aspx properly finds images/*.jpg, and helps me maintain my convention: ~/Areas/Candidate/Views/Job/Search.aspx -> ~/Assets/Candidate/Job/Search/images/*.jpg Perhaps with the ability to easily reference controller- or area-common assets manually or automatically: ~/Assets/Candidate/Job/images/*.jpg ~/Assets/Candidate/images/*.jpg If you wonder why I'm doing this, then speak up; I'm probably missing something. But here's why: I don't want stale static assets sitting in my ASP.NET MVC projects, which I expect to be an automatic outcome of the ~/Assets/Images folder: i.e. As a shared asset loses its last reference-count, who knows to delete it, especially with it being so difficult to trace content link validity in MVC projects? How do you, personally, do this? I can imagine, for example: Implement HtmlHelper extension methods for URL-generation. Extending ViewPage and ViewMasterPage with URL-generation methods. Implementing an inbound request filter to search related folders for static assets. and, are there good libraries out there for this? For example, something that also automatically appends timestamps for .JS and .CSS files, writes the / tags for me, and maybe even that allows me to inject includes in the head section from outside head code?

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