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  • Using VLOOKUP in Excel

    - by Mark Virtue
    VLOOKUP is one of Excel’s most useful functions, and it’s also one of the least understood.  In this article, we demystify VLOOKUP by way of a real-life example.  We’ll create a usable Invoice Template for a fictitious company. So what is VLOOKUP?  Well, of course it’s an Excel function.  This article will assume that the reader already has a passing understanding of Excel functions, and can use basic functions such as SUM, AVERAGE, and TODAY.  In its most common usage, VLOOKUP is a database function, meaning that it works with database tables – or more simply, lists of things in an Excel worksheet.  What sort of things?   Well, any sort of thing.  You may have a worksheet that contains a list of employees, or products, or customers, or CDs in your CD collection, or stars in the night sky.  It doesn’t really matter. Here’s an example of a list, or database.  In this case it’s a list of products that our fictitious company sells: Usually lists like this have some sort of unique identifier for each item in the list.  In this case, the unique identifier is in the “Item Code” column.  Note:  For the VLOOKUP function to work with a database/list, that list must have a column containing the unique identifier (or “key”, or “ID”), and that column must be the first column in the table.  Our sample database above satisfies this criterion. The hardest part of using VLOOKUP is understanding exactly what it’s for.  So let’s see if we can get that clear first: VLOOKUP retrieves information from a database/list based on a supplied instance of the unique identifier. Put another way, if you put the VLOOKUP function into a cell and pass it one of the unique identifiers from your database, it will return you one of the pieces of information associated with that unique identifier.  In the example above, you would pass VLOOKUP an item code, and it would return to you either the corresponding item’s description, its price, or its availability (its “In stock” quantity).  Which of these pieces of information will it pass you back?  Well, you get to decide this when you’re creating the formula. If all you need is one piece of information from the database, it would be a lot of trouble to go to to construct a formula with a VLOOKUP function in it.  Typically you would use this sort of functionality in a reusable spreadsheet, such as a template.  Each time someone enters a valid item code, the system would retrieve all the necessary information about the corresponding item. Let’s create an example of this:  An Invoice Template that we can reuse over and over in our fictitious company. First we start Excel… …and we create ourselves a blank invoice: This is how it’s going to work:  The person using the invoice template will fill in a series of item codes in column “A”, and the system will retrieve each item’s description and price, which will be used to calculate the line total for each item (assuming we enter a valid quantity). For the purposes of keeping this example simple, we will locate the product database on a separate sheet in the same workbook: In reality, it’s more likely that the product database would be located in a separate workbook.  It makes little difference to the VLOOKUP function, which doesn’t really care if the database is located on the same sheet, a different sheet, or a completely different workbook. In order to test the VLOOKUP formula we’re about to write, we first enter a valid item code into cell A11: Next, we move the active cell to the cell in which we want information retrieved from the database by VLOOKUP to be stored.  Interestingly, this is the step that most people get wrong.  To explain further:  We are about to create a VLOOKUP formula that will retrieve the description that corresponds to the item code in cell A11.  Where do we want this description put when we get it?  In cell B11, of course.  So that’s where we write the VLOOKUP formula – in cell B11. Select cell B11: We need to locate the list of all available functions that Excel has to offer, so that we can choose VLOOKUP and get some assistance in completing the formula.  This is found by first clicking the Formulas tab, and then clicking Insert Function:   A box appears that allows us to select any of the functions available in Excel.  To find the one we’re looking for, we could type a search term like “lookup” (because the function we’re interested in is a lookup function).  The system would return us a list of all lookup-related functions in Excel.  VLOOKUP is the second one in the list.  Select it an click OK… The Function Arguments box appears, prompting us for all the arguments (or parameters) needed in order to complete the VLOOKUP function.  You can think of this box as the function is asking us the following questions: What unique identifier are you looking up in the database? Where is the database? Which piece of information from the database, associated with the unique identifier, do you wish to have retrieved for you? The first three arguments are shown in bold, indicating that they are mandatory arguments (the VLOOKUP function is incomplete without them and will not return a valid value).  The fourth argument is not bold, meaning that it’s optional:   We will complete the arguments in order, top to bottom. The first argument we need to complete is the Lookup_value argument.  The function needs us to tell it where to find the unique identifier (the item code in this case) that it should be retuning the description of.  We must select the item code we entered earlier (in A11). Click on the selector icon to the right of the first argument: Then click once on the cell containing the item code (A11), and press Enter: The value of “A11” is inserted into the first argument. Now we need to enter a value for the Table_array argument.  In other words, we need to tell VLOOKUP where to find the database/list.  Click on the selector icon next to the second argument: Now locate the database/list and select the entire list – not including the header line.  The database is located on a separate worksheet, so we first click on that worksheet tab: Next we select the entire database, not including the header line: …and press Enter.  The range of cells that represents the database (in this case “’Product Database’!A2:D7”) is entered automatically for us into the second argument. Now we need to enter the third argument, Col_index_num.  We use this argument to specify to VLOOKUP which piece of information from the database, associate with our item code in A11, we wish to have returned to us.  In this particular example, we wish to have the item’s description returned to us.  If you look on the database worksheet, you’ll notice that the “Description” column is the second column in the database.  This means that we must enter a value of “2” into the Col_index_num box: It is important to note that that we are not entering a “2” here because the “Description” column is in the B column on that worksheet.  If the database happened to start in column K of the worksheet, we would still enter a “2” in this field. Finally, we need to decide whether to enter a value into the final VLOOKUP argument, Range_lookup.  This argument requires either a true or false value, or it should be left blank.  When using VLOOKUP with databases (as is true 90% of the time), then the way to decide what to put in this argument can be thought of as follows: If the first column of the database (the column that contains the unique identifiers) is sorted alphabetically/numerically in ascending order, then it’s possible to enter a value of true into this argument, or leave it blank. If the first column of the database is not sorted, or it’s sorted in descending order, then you must enter a value of false into this argument As the first column of our database is not sorted, we enter false into this argument: That’s it!  We’ve entered all the information required for VLOOKUP to return the value we need.  Click the OK button and notice that the description corresponding to item code “R99245” has been correctly entered into cell B11: The formula that was created for us looks like this: If we enter a different item code into cell A11, we will begin to see the power of the VLOOKUP function:  The description cell changes to match the new item code: We can perform a similar set of steps to get the item’s price returned into cell E11.  Note that the new formula must be created in cell E11.  The result will look like this: …and the formula will look like this: Note that the only difference between the two formulae is the third argument (Col_index_num) has changed from a “2” to a “3” (because we want data retrieved from the 3rd column in the database). If we decided to buy 2 of these items, we would enter a “2” into cell D11.  We would then enter a simple formula into cell F11 to get the line total: =D11*E11 …which looks like this… Completing the Invoice Template We’ve learned a lot about VLOOKUP so far.  In fact, we’ve learned all we’re going to learn in this article.  It’s important to note that VLOOKUP can be used in other circumstances besides databases.  This is less common, and may be covered in future How-To Geek articles. Our invoice template is not yet complete.  In order to complete it, we would do the following: We would remove the sample item code from cell A11 and the “2” from cell D11.  This will cause our newly created VLOOKUP formulae to display error messages: We can remedy this by judicious use of Excel’s IF() and ISBLANK() functions.  We change our formula from this…       =VLOOKUP(A11,’Product Database’!A2:D7,2,FALSE) …to this…       =IF(ISBLANK(A11),”",VLOOKUP(A11,’Product Database’!A2:D7,2,FALSE)) We would copy the formulas in cells B11, E11 and F11 down to the remainder of the item rows of the invoice.  Note that if we do this, the resulting formulas will no longer correctly refer to the database table.  We could fix this by changing the cell references for the database to absolute cell references.  Alternatively – and even better – we could create a range name for the entire product database (such as “Products”), and use this range name instead of the cell references.  The formula would change from this…       =IF(ISBLANK(A11),”",VLOOKUP(A11,’Product Database’!A2:D7,2,FALSE)) …to this…       =IF(ISBLANK(A11),”",VLOOKUP(A11,Products,2,FALSE)) …and then copy the formulas down to the rest of the invoice item rows. We would probably “lock” the cells that contain our formulae (or rather unlock the other cells), and then protect the worksheet, in order to ensure that our carefully constructed formulae are not accidentally overwritten when someone comes to fill in the invoice. We would save the file as a template, so that it could be reused by everyone in our company If we were feeling really clever, we would create a database of all our customers in another worksheet, and then use the customer ID entered in cell F5 to automatically fill in the customer’s name and address in cells B6, B7 and B8. If you would like to practice with VLOOKUP, or simply see our resulting Invoice Template, it can be downloaded from here. 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  • CodePlex Daily Summary for Sunday, June 03, 2012

    CodePlex Daily Summary for Sunday, June 03, 2012Popular ReleasesLiveChat Starter Kit: LCSK v1.5.2: New features: Visitor location (City - Country) from geo-location Pass configuration via javascript for the chat box New visitor identification (no more using the IP address as visitor identification) To update from 1.5.1 Run the /src/1.5.2-sql-updates.txt SQL script to update your database tables. If you have it installed via NuGet, simply update your package and the file will be included so you can run the update script. New installation The easiest way to add LCSK to your app is by...Prime Factorization: Prime Factorization V2: Download the installation package and run it, to install prime factorization on your computer.DNN Content Localization Tools: CLTools v0.4 (Beta4): 3th Beta release for DNN 6.1 and obove Bug corrections : - Copy module work againNTemplates: NTemplates full source code and examples: This release includes the following changes: - NTemplates code. More enhacements and bug fixing. Nested scans seems to be working ok now. New event: ScanStart. Very usuful for calculating totals (see the example) - Examples. 2 new examples on nested scans. One of them very simple I did just for debugging. The other one is a report of invoices grouped by vendor, including totals calculations. Planned Roadmap: - Work on fixing performance bottlenecek: Try to compile the expression...ZXMAK2: Version 2.6.2.3: - add support for ZIP files created on UNIX system; - improve WAV support (fixed PCM24, FLOAT32; added PCM32, FLOAT64); - fix drag-n-drop on modal dialogs; - tape AutoPlay feature (thanks to Woody for algorithm).Net Code Samples: Full WCF Duplex Service Example: Full WCF Duplex Service ExampleKendo UI ASP.NET Sample Applications: Sample Applications (2012-06-01): Sample application(s) demonstrating the use of Kendo UI in ASP.NET applications.Better Explorer: Better Explorer Beta 1: Finally, the first Beta is here! There were a lot of changes, including: Translations into 10 different languages (the translations are not complete and will be updated soon) Conditional Select new tools for managing archives Folder Tools tab new search bar and Search Tab new image editing tools update function many bug fixes, stability fixes, and memory leak fixes other new features as well! Please check it out and if there are any problems, let us know. :) Also, do not forge...myManga: myManga v1.0.0.3: Will include MangaPanda as a default option. ChangeLog Updating from Previous Version: Extract contents of Release - myManga v1.0.0.3.zip to previous version's folder. Replaces: myManga.exe BakaBox.dll CoreMangaClasses.dll Manga.dll Plugins/MangaReader.manga.dll Plugins/MangaFox.manga.dll Plugins/MangaHere.manga.dll Plugins/MangaPanda.manga.dllPlayer Framework by Microsoft: Player Framework for Windows 8 Metro (Preview 3): Player Framework for HTML/JavaScript and XAML/C# Metro Style Applications. Additional DownloadsIIS Smooth Streaming Client SDK for Windows 8 Microsoft PlayReady Client SDK for Metro Style Apps Release notes:Support for Windows 8 Release Preview (released 5/31/12) Advertising support (VAST, MAST, VPAID, & clips) Miscellaneous improvements and bug fixesMicrosoft Ajax Minifier: Microsoft Ajax Minifier 4.54: Fix for issue #18161: pretty-printing CSS @media rule throws an exception due to mismatched Indent/Unindent pair.Silverlight Toolkit: Silverlight 5 Toolkit Source - May 2012: Source code for December 2011 Silverlight 5 Toolkit release.Windows 8 Metro RSS Reader: RSS Reader release 6: Changed background and foreground colors Used VariableSizeGrid layout to wrap blog posts with images Sort items with Images first, text-only last Enabled Caching to improve navigation between framesJson.NET: Json.NET 4.5 Release 6: New feature - Added IgnoreDataMemberAttribute support New feature - Added GetResolvedPropertyName to DefaultContractResolver New feature - Added CheckAdditionalContent to JsonSerializer Change - Metro build now always uses late bound reflection Change - JsonTextReader no longer returns no content after consecutive underlying content read failures Fix - Fixed bad JSON in an array with error handling creating an infinite loop Fix - Fixed deserializing objects with a non-default cons...DotNetNuke® Community Edition CMS: 06.02.00: Major Highlights Fixed issue in the Site Settings when single quotes were being treated as escape characters Fixed issue loading the Mobile Premium Data after upgrading from CE to PE Fixed errors logged when updating folder provider settings Fixed the order of the mobile device capabilities in the Site Redirection Management UI The User Profile page was completely rebuilt. We needed User Profiles to have multiple child pages. This would allow for the most flexibility by still f...????: ????2.0.1: 1、?????。WiX Toolset: WiX v3.6 RC: WiX v3.6 RC (3.6.2928.0) provides feature complete Burn with VS11 support. For more information see Rob's blog post about the release: http://robmensching.com/blog/posts/2012/5/28/WiX-v3.6-Release-Candidate-availableJavascript .NET: Javascript .NET v0.7: SetParameter() reverts to its old behaviour of allowing JavaScript code to add new properties to wrapped C# objects. The behavior added briefly in 0.6 (throws an exception) can be had via the new SetParameterOptions.RejectUnknownProperties. TerminateExecution now uses its isolate to terminate the correct context automatically. Added support for converting all C# integral types, decimal and enums to JavaScript numbers. (Previously only the common types were handled properly.) Bug fixe...Phalanger - The PHP Language Compiler for the .NET Framework: 3.0 (May 2012): Fixes: unserialize() of negative float numbers fix pcre possesive quantifiers and character class containing ()[] array deserilization when the array contains a reference to ISerializable parsing lambda function fix round() reimplemented as it is in PHP to avoid .NET rounding errors filesize bypass for FileInfo.Length bug in Mono New features: Time zones reimplemented, uses Windows/Linux databaseSharePoint Euro 2012 - UEFA European Football Predictor: havivi.euro2012.wsp (1.1): New fetures:Admin enable / disable match Hide/Show Euro 2012 SharePoint lists (3 lists) Installing SharePoint Euro 2012 PredictorSharePoint Euro 2012 Predictor has been developed as a SharePoint Sandbox solution to support SharePoint Online (Office 365) Download the solution havivi.euro2012.wsp from the download page: Downloads Upload this solution to your Site Collection via the solutions area. Click on Activate to make the web parts in the solution available for use in the Site C...New ProjectsAFS.PhonePusherConnectorVX: pusher for phone vxApache: this is the Apache project.Apple: this is the Apple project.CUARTOAZZJL: HURRA!!Designing Windows 8 Applications with C# and XAML: This project hosts the source code used in the example projects for the book, Designing Windows 8 Metro Applications with C# and XAML.Easy Internet: CyberWeb ist ein einfacher Webbrowser für PC Neulinge. Ideal für Leute, die noch keine PC-Erfahrung haben.Easy Outlook Backup: Beschreibung: Easy Outlook Backup ist ein Programm das alle Daten von Outlook sichert. Ideal für Leute, die noch keine PC-Erfahrung haben. Easy Realtime Start: Beschreibung: Easy Realtime Start ist ein Programm das einen Prozess in höchster Priorität startet. Und das ganz bequem Per drag & drop. Ideal für Leute, die aufwendige Programme starten müssen. (zB.: “Blender” Free 3D Designer)eStock: eStock ist ein Verwaltungstool für Elektroniker um Bauteile im "Lager" sowie Projekte zu verwalten. Es bietet eine Möglichkeit festzulegen, um welche Art von Bauteil es sich handelt und wo sich dieses im Lager bzw. Regal befindet. Die Projektverwaltung ermöglicht es, Bauteile einem Projekt hinzuzufügen und eine Bestellliste / Einkaufsliste von Bauteilen, die nicht mehr im Lager vorhanden sind, zu erstellen. FuTTY: FireEgl's PuTTY -- FuTTY! FuTTY is a fork of PuTTY and PuTTYTray.GeometryWorld: To Do...Google: this is the Google project.Google Advance Search: An easy way to create documents search at Google and read your emails and Much moregoogle maps viewer for dynamics crm 2011: Easy google maps viewer for dynamics CRM 2011GPS Status - (GPS tool für GPS-Dongles und Mäuse) - GPS-Empfänger: Mein Programm verbindet sich mit dem externen GPS über einen Com-Port und bietet verschiedene Tools.Harmony Text Editor: Harmony is a ridiculously simple text editor for code and poetry.Hi! Football: .Goal / Objective -> To help friends gather for enjoying watching football together. .How it works -> To basically choose your favorite team, choose one of the matches fetched for his team, our app will generate a list of popular restraunts, cafes where he can watch the chosen match, the user can select one of the generated locations around his area, and create an event inviting his friends to join him and he can also join other friends' events.Java: this is the Java project.LevelUp Serializer: LevelUp Serializer is a small and simple serialize library.It can help developer to serialize and deserialize data more convenient. Feature: - Ease of use - Supports almost all serializer, like Binary、Xml、Soap、Json、DataContract. - Support serialize to file、serialize to stream、deserialize from file、deserialize from stream. - Support Xml encryption. - Support accelerated through the XML the serialization assemble.LFormatConvert: ????Linux???????????????????????,??ffmpeg????Machine QA Manager: Machine QA Manager is intended to save and help trend results from radiation therapy equipment testing. The program will be made as generic as possible from a initial setup to enable it's use for other types of routine testing activities (for example factory equipment) but preconfigured templates for radiation therapy will be supplied for the convenience of people working in that domain.maven-asbuild-plugin: maven-asbuild-plugin incorporates the adobe flash/flex based artifacts like swc or swf into the maven methology.Midnight Peach - C# framework generator for LINQ: C# framework generator for LINQMiku???????: ????????,????????!?????????????,??????????。?????????????????!MIKU????????????,??!????????????、????。 This program used to detect music beat.You can listen to music while press button,and it can display the BPM of the song.Miku will wave to you.MyTestingStudy: my personal testing studyNameless Sprite Editor: Nameless Sprite Editor is a tool used to thoroughly edit the graphics in ALL Game Boy Advance games. [ UNDER CONSTRUCTION ]NeoModulus Business Rules Builder: A windows form application that allows non-programmers to build strict definitions of a business domain. Once the definition is complete the program will build out object oriented C# files and a .net DLL. My test business domain is the open SRD, basically Dungeons and Dragons 3.5 edition.NodeJs: this is the NodeJs projectNoSQL: this is the Nosql project.OmniKassa for NopCommerce: OmniKassa payment module plugin for nopCommerceOn-Line Therapy: testOpen School: This project is about to create an open platform for all the academic institutions, so that they can manage all of their work. Our efforts will be for every kind of institution who are currently struggling with different kind of systems in place which are not collaborating with each other. This project will provide a common platform to all these kind of systems and provide them a better solution which actually works. Oracle: this is the Oracle project.Orchard Web Services: RESTful web services to expose interaction with Orchard content management.Personal Social Network using asp.net mvc and mongodb: FirstRooster is a network platform that let user create their own social network of interest to connect and share with like minded people anywhere.peshop: E-Commerce application , separated by DAl,BLL and Presentation layersPHP: this is the PHP project.Prime Factorization: Factoring trinomials using the ac method can be made easier through the use of Prime Factorization. Prime Factorization is a program that can assist you in the factoring of numbers in Algebra, namely trinomials using the AC Method. It can also find all the factors of any number.PromedioNotas: El programa trata de promediar 3 nostas y mostrar y si pasaba de año o no por medio de un mensajeProyecto Tarea: Este proyecto esta hecho con el objetivo de aprender sobre TFSProyectotarea1: Sotfware de terminal aéreo de Guayaquil, donde se encuentran el nombre de las aerolíneas y las rutas de vuelo a nivel nacional.Python: this is the Python project.Ruby: this is the Ruby project.tedplay: tedplay is your media player of choice for playing Commodore 264 music format files similar to SIDplay. It is basically a stripped down Commodore plus/4 emulator without video output and peripherals based on the SDL build of the Commodore 264 family emulator YAPE. tedplay is released under version 2 of the GNU Generic Public License and can be built for both Windows and Unix or actually any platform that has a C++ compiler and SDL support.test1: This is a test projectwin-x264: A port of the x264-codebase into a VisualStudio-project. Compilation requires Intel-compiler and Yasm.XDA ROM Hub: Xperia 2011 line toolkit.znvicente_cuartoc: Poyecto Vicente Eduardo Zambrano Navarrete??Win7?????: ??????? *.theme ???????(??,??,??,???)。????VSB???*.msstyles??,????????,????????????????????????!????????????,?????????????。???,????????! ?????????,?????????,????????,??????!?????????????,?????????????????,?????????,???Aero??,??????~?????????????!??,?????????theme??,?????????,??????,????,??????。 This program used to create .theme file and the relevant documents (wallpaper, pointer, ICONS, sounds, etc.). As long as you use VSB ready . msstyles files, chosen the icon wallpaper, etc, an...

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  • C#/.NET Little Wonders: ConcurrentBag and BlockingCollection

    - by James Michael Hare
    In the first week of concurrent collections, began with a general introduction and discussed the ConcurrentStack<T> and ConcurrentQueue<T>.  The last post discussed the ConcurrentDictionary<T> .  Finally this week, we shall close with a discussion of the ConcurrentBag<T> and BlockingCollection<T>. For more of the "Little Wonders" posts, see C#/.NET Little Wonders: A Redux. Recap As you'll recall from the previous posts, the original collections were object-based containers that accomplished synchronization through a Synchronized member.  With the advent of .NET 2.0, the original collections were succeeded by the generic collections which are fully type-safe, but eschew automatic synchronization.  With .NET 4.0, a new breed of collections was born in the System.Collections.Concurrent namespace.  Of these, the final concurrent collection we will examine is the ConcurrentBag and a very useful wrapper class called the BlockingCollection. For some excellent information on the performance of the concurrent collections and how they perform compared to a traditional brute-force locking strategy, see this informative whitepaper by the Microsoft Parallel Computing Platform team here. ConcurrentBag<T> – Thread-safe unordered collection. Unlike the other concurrent collections, the ConcurrentBag<T> has no non-concurrent counterpart in the .NET collections libraries.  Items can be added and removed from a bag just like any other collection, but unlike the other collections, the items are not maintained in any order.  This makes the bag handy for those cases when all you care about is that the data be consumed eventually, without regard for order of consumption or even fairness – that is, it’s possible new items could be consumed before older items given the right circumstances for a period of time. So why would you ever want a container that can be unfair?  Well, to look at it another way, you can use a ConcurrentQueue and get the fairness, but it comes at a cost in that the ordering rules and synchronization required to maintain that ordering can affect scalability a bit.  Thus sometimes the bag is great when you want the fastest way to get the next item to process, and don’t care what item it is or how long its been waiting. The way that the ConcurrentBag works is to take advantage of the new ThreadLocal<T> type (new in System.Threading for .NET 4.0) so that each thread using the bag has a list local to just that thread.  This means that adding or removing to a thread-local list requires very low synchronization.  The problem comes in where a thread goes to consume an item but it’s local list is empty.  In this case the bag performs “work-stealing” where it will rob an item from another thread that has items in its list.  This requires a higher level of synchronization which adds a bit of overhead to the take operation. So, as you can imagine, this makes the ConcurrentBag good for situations where each thread both produces and consumes items from the bag, but it would be less-than-idea in situations where some threads are dedicated producers and the other threads are dedicated consumers because the work-stealing synchronization would outweigh the thread-local optimization for a thread taking its own items. Like the other concurrent collections, there are some curiosities to keep in mind: IsEmpty(), Count, ToArray(), and GetEnumerator() lock collection Each of these needs to take a snapshot of whole bag to determine if empty, thus they tend to be more expensive and cause Add() and Take() operations to block. ToArray() and GetEnumerator() are static snapshots Because it is based on a snapshot, will not show subsequent updates after snapshot. Add() is lightweight Since adding to the thread-local list, there is very little overhead on Add. TryTake() is lightweight if items in thread-local list As long as items are in the thread-local list, TryTake() is very lightweight, much more so than ConcurrentStack() and ConcurrentQueue(), however if the local thread list is empty, it must steal work from another thread, which is more expensive. Remember, a bag is not ideal for all situations, it is mainly ideal for situations where a process consumes an item and either decomposes it into more items to be processed, or handles the item partially and places it back to be processed again until some point when it will complete.  The main point is that the bag works best when each thread both takes and adds items. For example, we could create a totally contrived example where perhaps we want to see the largest power of a number before it crosses a certain threshold.  Yes, obviously we could easily do this with a log function, but bare with me while I use this contrived example for simplicity. So let’s say we have a work function that will take a Tuple out of a bag, this Tuple will contain two ints.  The first int is the original number, and the second int is the last multiple of that number.  So we could load our bag with the initial values (let’s say we want to know the last multiple of each of 2, 3, 5, and 7 under 100. 1: var bag = new ConcurrentBag<Tuple<int, int>> 2: { 3: Tuple.Create(2, 1), 4: Tuple.Create(3, 1), 5: Tuple.Create(5, 1), 6: Tuple.Create(7, 1) 7: }; Then we can create a method that given the bag, will take out an item, apply the multiplier again, 1: public static void FindHighestPowerUnder(ConcurrentBag<Tuple<int,int>> bag, int threshold) 2: { 3: Tuple<int,int> pair; 4:  5: // while there are items to take, this will prefer local first, then steal if no local 6: while (bag.TryTake(out pair)) 7: { 8: // look at next power 9: var result = Math.Pow(pair.Item1, pair.Item2 + 1); 10:  11: if (result < threshold) 12: { 13: // if smaller than threshold bump power by 1 14: bag.Add(Tuple.Create(pair.Item1, pair.Item2 + 1)); 15: } 16: else 17: { 18: // otherwise, we're done 19: Console.WriteLine("Highest power of {0} under {3} is {0}^{1} = {2}.", 20: pair.Item1, pair.Item2, Math.Pow(pair.Item1, pair.Item2), threshold); 21: } 22: } 23: } Now that we have this, we can load up this method as an Action into our Tasks and run it: 1: // create array of tasks, start all, wait for all 2: var tasks = new[] 3: { 4: new Task(() => FindHighestPowerUnder(bag, 100)), 5: new Task(() => FindHighestPowerUnder(bag, 100)), 6: }; 7:  8: Array.ForEach(tasks, t => t.Start()); 9:  10: Task.WaitAll(tasks); Totally contrived, I know, but keep in mind the main point!  When you have a thread or task that operates on an item, and then puts it back for further consumption – or decomposes an item into further sub-items to be processed – you should consider a ConcurrentBag as the thread-local lists will allow for quick processing.  However, if you need ordering or if your processes are dedicated producers or consumers, this collection is not ideal.  As with anything, you should performance test as your mileage will vary depending on your situation! BlockingCollection<T> – A producers & consumers pattern collection The BlockingCollection<T> can be treated like a collection in its own right, but in reality it adds a producers and consumers paradigm to any collection that implements the interface IProducerConsumerCollection<T>.  If you don’t specify one at the time of construction, it will use a ConcurrentQueue<T> as its underlying store. If you don’t want to use the ConcurrentQueue, the ConcurrentStack and ConcurrentBag also implement the interface (though ConcurrentDictionary does not).  In addition, you are of course free to create your own implementation of the interface. So, for those who don’t remember the producers and consumers classical computer-science problem, the gist of it is that you have one (or more) processes that are creating items (producers) and one (or more) processes that are consuming these items (consumers).  Now, the crux of the problem is that there is a bin (queue) where the produced items are placed, and typically that bin has a limited size.  Thus if a producer creates an item, but there is no space to store it, it must wait until an item is consumed.  Also if a consumer goes to consume an item and none exists, it must wait until an item is produced. The BlockingCollection makes it trivial to implement any standard producers/consumers process set by providing that “bin” where the items can be produced into and consumed from with the appropriate blocking operations.  In addition, you can specify whether the bin should have a limited size or can be (theoretically) unbounded, and you can specify timeouts on the blocking operations. As far as your choice of “bin”, for the most part the ConcurrentQueue is the right choice because it is fairly light and maximizes fairness by ordering items so that they are consumed in the same order they are produced.  You can use the concurrent bag or stack, of course, but your ordering would be random-ish in the case of the former and LIFO in the case of the latter. So let’s look at some of the methods of note in BlockingCollection: BoundedCapacity returns capacity of the “bin” If the bin is unbounded, the capacity is int.MaxValue. Count returns an internally-kept count of items This makes it O(1), but if you modify underlying collection directly (not recommended) it is unreliable. CompleteAdding() is used to cut off further adds. This sets IsAddingCompleted and begins to wind down consumers once empty. IsAddingCompleted is true when producers are “done”. Once you are done producing, should complete the add process to alert consumers. IsCompleted is true when producers are “done” and “bin” is empty. Once you mark the producers done, and all items removed, this will be true. Add() is a blocking add to collection. If bin is full, will wait till space frees up Take() is a blocking remove from collection. If bin is empty, will wait until item is produced or adding is completed. GetConsumingEnumerable() is used to iterate and consume items. Unlike the standard enumerator, this one consumes the items instead of iteration. TryAdd() attempts add but does not block completely If adding would block, returns false instead, can specify TimeSpan to wait before stopping. TryTake() attempts to take but does not block completely Like TryAdd(), if taking would block, returns false instead, can specify TimeSpan to wait. Note the use of CompleteAdding() to signal the BlockingCollection that nothing else should be added.  This means that any attempts to TryAdd() or Add() after marked completed will throw an InvalidOperationException.  In addition, once adding is complete you can still continue to TryTake() and Take() until the bin is empty, and then Take() will throw the InvalidOperationException and TryTake() will return false. So let’s create a simple program to try this out.  Let’s say that you have one process that will be producing items, but a slower consumer process that handles them.  This gives us a chance to peek inside what happens when the bin is bounded (by default, the bin is NOT bounded). 1: var bin = new BlockingCollection<int>(5); Now, we create a method to produce items: 1: public static void ProduceItems(BlockingCollection<int> bin, int numToProduce) 2: { 3: for (int i = 0; i < numToProduce; i++) 4: { 5: // try for 10 ms to add an item 6: while (!bin.TryAdd(i, TimeSpan.FromMilliseconds(10))) 7: { 8: Console.WriteLine("Bin is full, retrying..."); 9: } 10: } 11:  12: // once done producing, call CompleteAdding() 13: Console.WriteLine("Adding is completed."); 14: bin.CompleteAdding(); 15: } And one to consume them: 1: public static void ConsumeItems(BlockingCollection<int> bin) 2: { 3: // This will only be true if CompleteAdding() was called AND the bin is empty. 4: while (!bin.IsCompleted) 5: { 6: int item; 7:  8: if (!bin.TryTake(out item, TimeSpan.FromMilliseconds(10))) 9: { 10: Console.WriteLine("Bin is empty, retrying..."); 11: } 12: else 13: { 14: Console.WriteLine("Consuming item {0}.", item); 15: Thread.Sleep(TimeSpan.FromMilliseconds(20)); 16: } 17: } 18: } Then we can fire them off: 1: // create one producer and two consumers 2: var tasks = new[] 3: { 4: new Task(() => ProduceItems(bin, 20)), 5: new Task(() => ConsumeItems(bin)), 6: new Task(() => ConsumeItems(bin)), 7: }; 8:  9: Array.ForEach(tasks, t => t.Start()); 10:  11: Task.WaitAll(tasks); Notice that the producer is faster than the consumer, thus it should be hitting a full bin often and displaying the message after it times out on TryAdd(). 1: Consuming item 0. 2: Consuming item 1. 3: Bin is full, retrying... 4: Bin is full, retrying... 5: Consuming item 3. 6: Consuming item 2. 7: Bin is full, retrying... 8: Consuming item 4. 9: Consuming item 5. 10: Bin is full, retrying... 11: Consuming item 6. 12: Consuming item 7. 13: Bin is full, retrying... 14: Consuming item 8. 15: Consuming item 9. 16: Bin is full, retrying... 17: Consuming item 10. 18: Consuming item 11. 19: Bin is full, retrying... 20: Consuming item 12. 21: Consuming item 13. 22: Bin is full, retrying... 23: Bin is full, retrying... 24: Consuming item 14. 25: Adding is completed. 26: Consuming item 15. 27: Consuming item 16. 28: Consuming item 17. 29: Consuming item 19. 30: Consuming item 18. Also notice that once CompleteAdding() is called and the bin is empty, the IsCompleted property returns true, and the consumers will exit. Summary The ConcurrentBag is an interesting collection that can be used to optimize concurrency scenarios where tasks or threads both produce and consume items.  In this way, it will choose to consume its own work if available, and then steal if not.  However, in situations where you want fair consumption or ordering, or in situations where the producers and consumers are distinct processes, the bag is not optimal. The BlockingCollection is a great wrapper around all of the concurrent queue, stack, and bag that allows you to add producer and consumer semantics easily including waiting when the bin is full or empty. That’s the end of my dive into the concurrent collections.  I’d also strongly recommend, once again, you read this excellent Microsoft white paper that goes into much greater detail on the efficiencies you can gain using these collections judiciously (here). Tweet Technorati Tags: C#,.NET,Concurrent Collections,Little Wonders

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  • SQLAuthority News – Job Interviewing the Right Way (and for the Right Reasons) – Guest Post by Feodor Georgiev

    - by pinaldave
    Feodor Georgiev is a SQL Server database specialist with extensive experience of thinking both within and outside the box. He has wide experience of different systems and solutions in the fields of architecture, scalability, performance, etc. Feodor has experience with SQL Server 2000 and later versions, and is certified in SQL Server 2008. Feodor has written excellent article on Job Interviewing the Right Way. Here is his article in his own language. A while back I was thinking to start a blog post series on interviewing and employing IT personnel. At that time I had just read the ‘Smart and gets things done’ book (http://www.joelonsoftware.com/items/2007/06/05.html) and I was hyped up on some debatable topics regarding finding and employing the best people in the branch. I have no problem with hiring the best of the best; it’s just the definition of ‘the best of the best’ that makes things a bit more complicated. One of the fundamental books one can read on the topic of interviewing is the one mentioned above. If you have not read it, then you must do so; not because it contains the ultimate truth, and not because it gives the answers to most questions on the subject, but because the book contains an extensive set of questions about interviewing and employing people. Of course, a big part of these questions have different answers, depending on location, culture, available funds and so on. (What works in the US may not necessarily work in the Nordic countries or India, or it may work in a different way). The only thing that is valid regardless of any external factor is this: curiosity. In my belief there are two kinds of people – curious and not-so-curious; regardless of profession. Think about it – professional success is directly proportional to the individual’s curiosity + time of active experience in the field. (I say ‘active experience’ because vacations and any distractions do not count as experience :)  ) So, curiosity is the factor which will distinguish a good employee from the not-so-good one. But let’s shift our attention to something else for now: a few tips and tricks for successful interviews. Tip and trick #1: get your priorities straight. Your status usually dictates your priorities; for example, if the person looking for a job has just relocated to a new country, they might tend to ignore some of their priorities and overload others. In other words, setting priorities straight means to define the personal criteria by which the interview process is lead. For example, similar to the following questions can help define the criteria for someone looking for a job: How badly do I need a (any) job? Is it more important to work in a clean and quiet environment or is it important to get paid well (or both, if possible)? And so on… Furthermore, before going to the interview, the candidate should have a list of priorities, sorted by the most importance: e.g. I want a quiet environment, x amount of money, great helping boss, a desk next to a window and so on. Also it is a good idea to be prepared and know which factors can be compromised and to what extent. Tip and trick #2: the interview is a two-way street. A job candidate should not forget that the interview process is not a one-way street. What I mean by this is that while the employer is interviewing the potential candidate, the job seeker should not miss the chance to interview the employer. Usually, the employer and the candidate will meet for an interview and talk about a variety of topics. In a quality interview the candidate will be presented to key members of the team and will have the opportunity to ask them questions. By asking the right questions both parties will define their opinion about each other. For example, if the candidate talks to one of the potential bosses during the interview process and they notice that the potential manager has a hard time formulating a question, then it is up to the candidate to decide whether working with such person is a red flag for them. There are as many interview processes out there as there are companies and each one is different. Some bigger companies and corporates can afford pre-selection processes, 3 or even 4 stages of interviews, small companies usually settle with one interview. Some companies even give cognitive tests on the interview. Why not? In his book Joel suggests that a good candidate should be pampered and spoiled beyond belief with a week-long vacation in New York, fancy hotels, food and who knows what. For all I can imagine, an interview might even take place at the top of the Eifel tower (right, Mr. Joel, right?) I doubt, however, that this is the optimal way to capture the attention of a good employee. The ‘curiosity’ topic What I have learned so far in my professional experience is that opinions can be subjective. Plus, opinions on technology subjects can also be subjective. According to Joel, only hiring the best of the best is worth it. If you ask me, there is no such thing as best of the best, simply because human nature (well, aside from some physical limitations, like putting your pants on through your head :) ) has no boundaries. And why would it have boundaries? I have seen many curious and interesting people, naturally good at technology, though uninterested in it as one  can possibly be; I have also seen plenty of people interested in technology, who (in an ideal world) should have stayed far from it. At any rate, all of this sums up at the end to the ‘supply and demand’ factor. The interview process big-bang boils down to this: If there is a mutual benefit for both the employer and the potential employee to work together, then it all sorts out nicely. If there is no benefit, then it is much harder to get to a common place. Tip and trick #3: word-of-mouth is worth a thousand words Here I would just mention that the best thing a job candidate can get during the interview process is access to future team members or other employees of the new company. Nowadays the world has become quite small and everyone knows everyone. Look at LinkedIn, look at other professional networks and you will realize how small the world really is. Knowing people is a good way to become more approachable and to approach them. Tip and trick #4: Be confident. It is true that for some people confidence is as natural as breathing and others have to work hard to express it. Confidence is, however, a key factor in convincing the other side (potential employer or employee) that there is a great chance for success by working together. But it cannot get you very far if it’s not backed up by talent, curiosity and knowledge. Tip and trick #5: The right reasons What really bothers me in Sweden (and I am sure that there are similar situations in other countries) is that there is a tendency to fill quotas and to filter out candidates by criteria different from their skill and knowledge. In job ads I see quite often the phrases ‘positive thinker’, ‘team player’ and many similar hints about personality features. So my guess here is that discrimination has evolved to a new level. Let me clear up the definition of discrimination: ‘unfair treatment of a person or group on the basis of prejudice’. And prejudice is the ‘partiality that prevents objective consideration of an issue or situation’. In other words, there is not much difference whether a job candidate is filtered out by race, gender or by personality features – it is all a bad habit. And in reality, there is no proven correlation between the technology knowledge paired with skills and the personal features (gender, race, age, optimism). It is true that a significantly greater number of Darwin awards were given to men than to women, but I am sure that somewhere there is a paper or theory explaining the genetics behind this. J This topic actually brings to mind one of my favorite work related stories. A while back I was working for a big company with many teams involved in their processes. One of the teams was occupying 2 rooms – one had the team members and was full of light, colorful posters, chit-chats and giggles, whereas the other room was dark, lighted only by a single monitor with a quiet person in front of it. Later on I realized that the ‘dark room’ person was the guru and the ultimate problem-solving-brain who did not like the chats and giggles and hence was in a separate room. In reality, all severe problems which the chatty and cheerful team members could not solve and all emergencies were directed to ‘the dark room’. And thus all worked out well. The moral of the story: Personality has nothing to do with technology knowledge and skills. End of story. Summary: I’d like to stress the fact that there is no ultimately perfect candidate for a job, and there is no such thing as ‘best-of-the-best’. From my personal experience, the main criteria by which I measure people (co-workers and bosses) is the curiosity factor; I know from experience that the more curious and inventive a person is, the better chances there are for great achievements in their field. Related stories: (for extra credit) 1) Get your priorities straight. A while back as a consultant I was working for a few days at a time at different offices and for different clients, and so I was able to compare and analyze the work environments. There were two different places which I compared and recently I asked a friend of mine the following question: “Which one would you prefer as a work environment: a noisy office full of people, or a quiet office full of faulty smells because the office is rarely cleaned?” My friend was puzzled for a while, thought about it and said: “Hmm, you are talking about two different kinds of pollution… I will probably choose the second, since I can clean the workplace myself a bit…” 2) The interview is a two-way street. One time, during a job interview, I met a potential boss that had a hard time phrasing a question. At that particular time it was clear to me that I would not have liked to work under this person. According to my work religion, the properly asked question contains at least half of the answer. And if I work with someone who cannot ask a question… then I’d be doing double or triple work. At another interview, after the technical part with the team leader of the department, I was introduced to one of the team members and we were left alone for 5 minutes. I immediately jumped on the occasion and asked the blunt question: ‘What have you learned here for the past year and how do you like your job?’ The team member looked at me and said ‘Nothing really. I like playing with my cats at home, so I am out of here at 5pm and I don’t have time for much.’ I was disappointed at the time and I did not take the job offer. I wasn’t that shocked a few months later when the company went bankrupt. 3) The right reasons to take a job: personality check. A while back I was asked to serve as a job reference for a coworker. I agreed, and after some weeks I got a phone call from the company where my colleague was applying for a job. The conversation started with the manager’s question about my colleague’s personality and about their social skills. (You can probably guess what my internal reaction was… J ) So, after 30 minutes of pouring common sense into the interviewer’s head, we finally agreed on the fact that a shy or quiet personality has nothing to do with work skills and knowledge. Some years down the road my former colleague is taking the manager’s position as the manager is demoted to a different department. Reference: Feodor Georgiev, Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, Readers Contribution, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • Creating ASP.NET MVC Negotiated Content Results

    - by Rick Strahl
    In a recent ASP.NET MVC application I’m involved with, we had a late in the process request to handle Content Negotiation: Returning output based on the HTTP Accept header of the incoming HTTP request. This is standard behavior in ASP.NET Web API but ASP.NET MVC doesn’t support this functionality directly out of the box. Another reason this came up in discussion is last week’s announcements of ASP.NET vNext, which seems to indicate that ASP.NET Web API is not going to be ported to the cloud version of vNext, but rather be replaced by a combined version of MVC and Web API. While it’s not clear what new API features will show up in this new framework, it’s pretty clear that the ASP.NET MVC style syntax will be the new standard for all the new combined HTTP processing framework. Why negotiated Content? Content negotiation is one of the key features of Web API even though it’s such a relatively simple thing. But it’s also something that’s missing in MVC and once you get used to automatically having your content returned based on Accept headers it’s hard to go back to manually having to create separate methods for different output types as you’ve had to with Microsoft server technologies all along (yes, yes I know other frameworks – including my own – have done this for years but for in the box features this is relatively new from Web API). As a quick review,  Accept Header content negotiation works off the request’s HTTP Accept header:POST http://localhost/mydailydosha/Editable/NegotiateContent HTTP/1.1 Content-Type: application/json Accept: application/json Host: localhost Content-Length: 76 Pragma: no-cache { ElementId: "header", PageName: "TestPage", Text: "This is a nice header" } If I make this request I would expect to get back a JSON result based on my application/json Accept header. To request XML  I‘d just change the accept header:Accept: text/xml and now I’d expect the response to come back as XML. Now this only works with media types that the server can process. In my case here I need to handle JSON, XML, HTML (using Views) and Plain Text. HTML results might need more than just a data return – you also probably need to specify a View to render the data into either by specifying the view explicitly or by using some sort of convention that can automatically locate a view to match. Today ASP.NET MVC doesn’t support this sort of automatic content switching out of the box. Unfortunately, in my application scenario we have an application that started out primarily with an AJAX backend that was implemented with JSON only. So there are lots of JSON results like this:[Route("Customers")] public ActionResult GetCustomers() { return Json(repo.GetCustomers(),JsonRequestBehavior.AllowGet); } These work fine, but they are of course JSON specific. Then a couple of weeks ago, a requirement came in that an old desktop application needs to also consume this API and it has to use XML to do it because there’s no JSON parser available for it. Ooops – stuck with JSON in this case. While it would have been easy to add XML specific methods I figured it’s easier to add basic content negotiation. And that’s what I show in this post. Missteps – IResultFilter, IActionFilter My first attempt at this was to use IResultFilter or IActionFilter which look like they would be ideal to modify result content after it’s been generated using OnResultExecuted() or OnActionExecuted(). Filters are great because they can look globally at all controller methods or individual methods that are marked up with the Filter’s attribute. But it turns out these filters don’t work for raw POCO result values from Action methods. What we wanted to do for API calls is get back to using plain .NET types as results rather than result actions. That is  you write a method that doesn’t return an ActionResult, but a standard .NET type like this:public Customer UpdateCustomer(Customer cust) { … do stuff to customer :-) return cust; } Unfortunately both OnResultExecuted and OnActionExecuted receive an MVC ContentResult instance from the POCO object. MVC basically takes any non-ActionResult return value and turns it into a ContentResult by converting the value using .ToString(). Ugh. The ContentResult itself doesn’t contain the original value, which is lost AFAIK with no way to retrieve it. So there’s no way to access the raw customer object in the example above. Bummer. Creating a NegotiatedResult This leaves mucking around with custom ActionResults. ActionResults are MVC’s standard way to return action method results – you basically specify that you would like to render your result in a specific format. Common ActionResults are ViewResults (ie. View(vn,model)), JsonResult, RedirectResult etc. They work and are fairly effective and work fairly well for testing as well as it’s the ‘standard’ interface to return results from actions. The problem with the this is mainly that you’re explicitly saying that you want a specific result output type. This works well for many things, but sometimes you do want your result to be negotiated. My first crack at this solution here is to create a simple ActionResult subclass that looks at the Accept header and based on that writes the output. I need to support JSON and XML content and HTML as well as text – so effectively 4 media types: application/json, text/xml, text/html and text/plain. Everything else is passed through as ContentResult – which effecively returns whatever .ToString() returns. Here’s what the NegotiatedResult usage looks like:public ActionResult GetCustomers() { return new NegotiatedResult(repo.GetCustomers()); } public ActionResult GetCustomer(int id) { return new NegotiatedResult("Show", repo.GetCustomer(id)); } There are two overloads of this method – one that returns just the raw result value and a second version that accepts an optional view name. The second version returns the Razor view specified only if text/html is requested – otherwise the raw data is returned. This is useful in applications where you have an HTML front end that can also double as an API interface endpoint that’s using the same model data you send to the View. For the application I mentioned above this was another actual use-case we needed to address so this was a welcome side effect of creating a custom ActionResult. There’s also an extension method that directly attaches a Negotiated() method to the controller using the same syntax:public ActionResult GetCustomers() { return this.Negotiated(repo.GetCustomers()); } public ActionResult GetCustomer(int id) { return this.Negotiated("Show",repo.GetCustomer(id)); } Using either of these mechanisms now allows you to return JSON, XML, HTML or plain text results depending on the Accept header sent. Send application/json you get just the Customer JSON data. Ditto for text/xml and XML data. Pass text/html for the Accept header and the "Show.cshtml" Razor view is rendered passing the result model data producing final HTML output. While this isn’t as clean as passing just POCO objects back as I had intended originally, this approach fits better with how MVC action methods are intended to be used and we get the bonus of being able to specify a View to render (optionally) for HTML. How does it work An ActionResult implementation is pretty straightforward. You inherit from ActionResult and implement the ExecuteResult method to send your output to the ASP.NET output stream. ActionFilters are an easy way to effectively do post processing on ASP.NET MVC controller actions just before the content is sent to the output stream, assuming your specific action result was used. Here’s the full code to the NegotiatedResult class (you can also check it out on GitHub):/// <summary> /// Returns a content negotiated result based on the Accept header. /// Minimal implementation that works with JSON and XML content, /// can also optionally return a view with HTML. /// </summary> /// <example> /// // model data only /// public ActionResult GetCustomers() /// { /// return new NegotiatedResult(repo.Customers.OrderBy( c=> c.Company) ) /// } /// // optional view for HTML /// public ActionResult GetCustomers() /// { /// return new NegotiatedResult("List", repo.Customers.OrderBy( c=> c.Company) ) /// } /// </example> public class NegotiatedResult : ActionResult { /// <summary> /// Data stored to be 'serialized'. Public /// so it's potentially accessible in filters. /// </summary> public object Data { get; set; } /// <summary> /// Optional name of the HTML view to be rendered /// for HTML responses /// </summary> public string ViewName { get; set; } public static bool FormatOutput { get; set; } static NegotiatedResult() { FormatOutput = HttpContext.Current.IsDebuggingEnabled; } /// <summary> /// Pass in data to serialize /// </summary> /// <param name="data">Data to serialize</param> public NegotiatedResult(object data) { Data = data; } /// <summary> /// Pass in data and an optional view for HTML views /// </summary> /// <param name="data"></param> /// <param name="viewName"></param> public NegotiatedResult(string viewName, object data) { Data = data; ViewName = viewName; } public override void ExecuteResult(ControllerContext context) { if (context == null) throw new ArgumentNullException("context"); HttpResponseBase response = context.HttpContext.Response; HttpRequestBase request = context.HttpContext.Request; // Look for specific content types if (request.AcceptTypes.Contains("text/html")) { response.ContentType = "text/html"; if (!string.IsNullOrEmpty(ViewName)) { var viewData = context.Controller.ViewData; viewData.Model = Data; var viewResult = new ViewResult { ViewName = ViewName, MasterName = null, ViewData = viewData, TempData = context.Controller.TempData, ViewEngineCollection = ((Controller)context.Controller).ViewEngineCollection }; viewResult.ExecuteResult(context.Controller.ControllerContext); } else response.Write(Data); } else if (request.AcceptTypes.Contains("text/plain")) { response.ContentType = "text/plain"; response.Write(Data); } else if (request.AcceptTypes.Contains("application/json")) { using (JsonTextWriter writer = new JsonTextWriter(response.Output)) { var settings = new JsonSerializerSettings(); if (FormatOutput) settings.Formatting = Newtonsoft.Json.Formatting.Indented; JsonSerializer serializer = JsonSerializer.Create(settings); serializer.Serialize(writer, Data); writer.Flush(); } } else if (request.AcceptTypes.Contains("text/xml")) { response.ContentType = "text/xml"; if (Data != null) { using (var writer = new XmlTextWriter(response.OutputStream, new UTF8Encoding())) { if (FormatOutput) writer.Formatting = System.Xml.Formatting.Indented; XmlSerializer serializer = new XmlSerializer(Data.GetType()); serializer.Serialize(writer, Data); writer.Flush(); } } } else { // just write data as a plain string response.Write(Data); } } } /// <summary> /// Extends Controller with Negotiated() ActionResult that does /// basic content negotiation based on the Accept header. /// </summary> public static class NegotiatedResultExtensions { /// <summary> /// Return content-negotiated content of the data based on Accept header. /// Supports: /// application/json - using JSON.NET /// text/xml - Xml as XmlSerializer XML /// text/html - as text, or an optional View /// text/plain - as text /// </summary> /// <param name="controller"></param> /// <param name="data">Data to return</param> /// <returns>serialized data</returns> /// <example> /// public ActionResult GetCustomers() /// { /// return this.Negotiated( repo.Customers.OrderBy( c=> c.Company) ) /// } /// </example> public static NegotiatedResult Negotiated(this Controller controller, object data) { return new NegotiatedResult(data); } /// <summary> /// Return content-negotiated content of the data based on Accept header. /// Supports: /// application/json - using JSON.NET /// text/xml - Xml as XmlSerializer XML /// text/html - as text, or an optional View /// text/plain - as text /// </summary> /// <param name="controller"></param> /// <param name="viewName">Name of the View to when Accept is text/html</param> /// /// <param name="data">Data to return</param> /// <returns>serialized data</returns> /// <example> /// public ActionResult GetCustomers() /// { /// return this.Negotiated("List", repo.Customers.OrderBy( c=> c.Company) ) /// } /// </example> public static NegotiatedResult Negotiated(this Controller controller, string viewName, object data) { return new NegotiatedResult(viewName, data); } } Output Generation – JSON and XML Generating output for XML and JSON is simple – you use the desired serializer and off you go. Using XmlSerializer and JSON.NET it’s just a handful of lines each to generate serialized output directly into the HTTP output stream. Please note this implementation uses JSON.NET for its JSON generation rather than the default JavaScriptSerializer that MVC uses which I feel is an additional bonus to implementing this custom action. I’d already been using a custom JsonNetResult class previously, but now this is just rolled into this custom ActionResult. Just keep in mind that JSON.NET outputs slightly different JSON for certain things like collections for example, so behavior may change. One addition to this implementation might be a flag to allow switching the JSON serializer. Html View Generation Html View generation actually turned out to be easier than anticipated. Initially I used my generic ASP.NET ViewRenderer Class that can render MVC views from any ASP.NET application. However it turns out since we are executing inside of an active MVC request there’s an easier way: We can simply create a custom ViewResult and populate its members and then execute it. The code in text/html handling code that renders the view is simply this:response.ContentType = "text/html"; if (!string.IsNullOrEmpty(ViewName)) { var viewData = context.Controller.ViewData; viewData.Model = Data; var viewResult = new ViewResult { ViewName = ViewName, MasterName = null, ViewData = viewData, TempData = context.Controller.TempData, ViewEngineCollection = ((Controller)context.Controller).ViewEngineCollection }; viewResult.ExecuteResult(context.Controller.ControllerContext); } else response.Write(Data); which is a neat and easy way to render a Razor view assuming you have an active controller that’s ready for rendering. Sweet – dependency removed which makes this class self-contained without any external dependencies other than JSON.NET. Summary While this isn’t exactly a new topic, it’s the first time I’ve actually delved into this with MVC. I’ve been doing content negotiation with Web API and prior to that with my REST library. This is the first time it’s come up as an issue in MVC. But as I have worked through this I find that having a way to specify both HTML Views *and* JSON and XML results from a single controller certainly is appealing to me in many situations as we are in this particular application returning identical data models for each of these operations. Rendering content negotiated views is something that I hope ASP.NET vNext will provide natively in the combined MVC and WebAPI model, but we’ll see how this actually will be implemented. In the meantime having a custom ActionResult that provides this functionality is a workable and easily adaptable way of handling this going forward. Whatever ends up happening in ASP.NET vNext the abstraction can probably be changed to support the native features of the future. Anyway I hope some of you found this useful if not for direct integration then as insight into some of the rendering logic that MVC uses to get output into the HTTP stream… Related Resources Latest Version of NegotiatedResult.cs on GitHub Understanding Action Controllers Rendering ASP.NET Views To String© Rick Strahl, West Wind Technologies, 2005-2014Posted in MVC  ASP.NET  HTTP   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • Unexpected start of already-primary server processes when heartbeat on secondary is stopped.

    - by vorik
    Hi, I've got an active-passive Heartbeat cluster with Apache, MySQL, ActiveMQ and DRBD. Today, I wanted to perform hardware-maintenance on the secondary node (node04), so I stopped the heartbeat service before shutting it down. Then, the primary node (node03) received a shutdown notice from the secondary node (node04). This logging comes from the primary node: node03 heartbeat[4458]: 2010/03/08_08:52:56 info: Received shutdown notice from 'node04.companydomain.nl'. heartbeat[4458]: 2010/03/08_08:52:56 info: Resources being acquired from node04.companydomain.nl. harc[27522]: 2010/03/08_08:52:56 info: Running /etc/ha.d/rc.d/status status heartbeat[27523]: 2010/03/08_08:52:56 info: Local Resource acquisition completed. mach_down[27567]: 2010/03/08_08:52:56 info: /usr/share/heartbeat/mach_down: nice_failback: foreign resources acquired mach_down[27567]: 2010/03/08_08:52:56 info: mach_down takeover complete for node node04.companydomain.nl. heartbeat[4458]: 2010/03/08_08:52:56 info: mach_down takeover complete. harc[27620]: 2010/03/08_08:52:56 info: Running /etc/ha.d/rc.d/ip-request-resp ip-request-resp ip-request-resp[27620]: 2010/03/08_08:52:56 received ip-request-resp drbddisk OK yes ResourceManager[27645]: 2010/03/08_08:52:56 info: Acquiring resource group: node03.companydomain.nl drbddisk Filesystem::/dev/drbd0::/data::ext3 mysql apache::/etc/httpd/conf/httpd.conf LVSSyncDaemonSwap::master monitor activemq tivoli-cluster MailTo::[email protected]::DRBDFailureDrisAcc MailTo::[email protected]::DRBDFailureDrisAcc 1.2.3.212 ResourceManager[27645]: 2010/03/08_08:52:56 info: Running /etc/ha.d/resource.d/drbddisk start Filesystem[27700]: 2010/03/08_08:52:57 INFO: Running OK ResourceManager[27645]: 2010/03/08_08:52:57 info: Running /etc/ha.d/resource.d/mysql start mysql[27783]: 2010/03/08_08:52:57 Starting MySQL[ OK ] apache[27853]: 2010/03/08_08:52:57 INFO: Running OK ResourceManager[27645]: 2010/03/08_08:52:57 info: Running /etc/ha.d/resource.d/monitor start monitor[28160]: 2010/03/08_08:52:58 ResourceManager[27645]: 2010/03/08_08:52:58 info: Running /etc/ha.d/resource.d/activemq start activemq[28210]: 2010/03/08_08:52:58 Starting ActiveMQ Broker... ActiveMQ Broker is already running. ResourceManager[27645]: 2010/03/08_08:52:58 ERROR: Return code 1 from /etc/ha.d/resource.d/activemq ResourceManager[27645]: 2010/03/08_08:52:58 CRIT: Giving up resources due to failure of activemq ResourceManager[27645]: 2010/03/08_08:52:58 info: Releasing resource group: node03.companydomain.nl drbddisk Filesystem::/dev/drbd0::/data::ext3 mysql apache::/etc/httpd/conf/httpd.conf LVSSyncDaemonSwap::master monitor activemq tivoli-cluster MailTo::[email protected]::DRBDFailureDrisAcc MailTo::[email protected]::DRBDFailureDrisAcc 1.2.3.212 ResourceManager[27645]: 2010/03/08_08:52:58 info: Running /etc/ha.d/resource.d/IPaddr 1.2.3.212 stop IPaddr[28329]: 2010/03/08_08:52:58 INFO: ifconfig eth0:0 down IPaddr[28312]: 2010/03/08_08:52:58 INFO: Success ResourceManager[27645]: 2010/03/08_08:52:58 info: Running /etc/ha.d/resource.d/MailTo [email protected] DRBDFailureDrisAcc stop MailTo[28378]: 2010/03/08_08:52:58 INFO: Success ResourceManager[27645]: 2010/03/08_08:52:58 info: Running /etc/ha.d/resource.d/MailTo [email protected] DRBDFailureDrisAcc stop MailTo[28433]: 2010/03/08_08:52:58 INFO: Success ResourceManager[27645]: 2010/03/08_08:52:58 info: Running /etc/ha.d/resource.d/tivoli-cluster stop ResourceManager[27645]: 2010/03/08_08:52:58 info: Running /etc/ha.d/resource.d/activemq stop activemq[28503]: 2010/03/08_08:53:01 Stopping ActiveMQ Broker... Stopped ActiveMQ Broker. ResourceManager[27645]: 2010/03/08_08:53:01 info: Running /etc/ha.d/resource.d/monitor stop monitor[28681]: 2010/03/08_08:53:01 ResourceManager[27645]: 2010/03/08_08:53:01 info: Running /etc/ha.d/resource.d/LVSSyncDaemonSwap master stop LVSSyncDaemonSwap[28714]: 2010/03/08_08:53:02 info: ipvs_syncmaster down LVSSyncDaemonSwap[28714]: 2010/03/08_08:53:02 info: ipvs_syncbackup up LVSSyncDaemonSwap[28714]: 2010/03/08_08:53:02 info: ipvs_syncmaster released ResourceManager[27645]: 2010/03/08_08:53:02 info: Running /etc/ha.d/resource.d/apache /etc/httpd/conf/httpd.conf stop apache[28782]: 2010/03/08_08:53:03 INFO: Killing apache PID 18390 apache[28782]: 2010/03/08_08:53:03 INFO: apache stopped. apache[28771]: 2010/03/08_08:53:03 INFO: Success ResourceManager[27645]: 2010/03/08_08:53:03 info: Running /etc/ha.d/resource.d/mysql stop mysql[28851]: 2010/03/08_08:53:24 Shutting down MySQL.....................[ OK ] ResourceManager[27645]: 2010/03/08_08:53:24 info: Running /etc/ha.d/resource.d/Filesystem /dev/drbd0 /data ext3 stop Filesystem[29010]: 2010/03/08_08:53:25 INFO: Running stop for /dev/drbd0 on /data Filesystem[29010]: 2010/03/08_08:53:25 INFO: Trying to unmount /data Filesystem[29010]: 2010/03/08_08:53:25 ERROR: Couldn't unmount /data; trying cleanup with SIGTERM Filesystem[29010]: 2010/03/08_08:53:25 INFO: Some processes on /data were signalled Filesystem[29010]: 2010/03/08_08:53:27 INFO: unmounted /data successfully Filesystem[28999]: 2010/03/08_08:53:27 INFO: Success ResourceManager[27645]: 2010/03/08_08:53:27 info: Running /etc/ha.d/resource.d/drbddisk stop heartbeat[4458]: 2010/03/08_08:53:29 WARN: node node04.companydomain.nl: is dead heartbeat[4458]: 2010/03/08_08:53:29 info: Dead node node04.companydomain.nl gave up resources. heartbeat[4458]: 2010/03/08_08:53:29 info: Link node04.companydomain.nl:eth0 dead. heartbeat[4458]: 2010/03/08_08:53:29 info: Link node04.companydomain.nl:eth1 dead. hb_standby[29193]: 2010/03/08_08:53:57 Going standby [foreign]. heartbeat[4458]: 2010/03/08_08:53:57 info: node03.companydomain.nl wants to go standby [foreign] Soo... What just happened here??? Heartbeat on node04 stopped and told node03, which was the active node at the time. Somehow, node03 decided to start the cluster processes that were already running. (For the processes that are not critical, I always return a 0 from the startupscript so it does not stops the entire cluster when a non-essential part fails.) When starting ActiveMQ, it returns status 1 because it is already running. This fails the node and shuts everything down. As heartbeat is not running on the secondary node, it cannot failover to there. When I tried to run ha_takeover to restart the resources, absolutely nothing happened. Only after I restarted heartbeat on the primary node the resources could be started (after a delay of 2 minutes). These are my questions: Why does heartbeat on the primary node try to start the cluster processes again? Why did ha_takeover not work? What can I do to prevent this from happening? Server configuration: DRBD: version: 8.3.7 (api:88/proto:86-91) GIT-hash: ea9e28dbff98e331a62bcbcc63a6135808fe2917 build by [email protected], 2010-01-20 09:14:48 0: cs:Connected ro:Secondary/Primary ds:UpToDate/UpToDate B r---- ns:0 nr:6459432 dw:6459432 dr:0 al:0 bm:301 lo:0 pe:0 ua:0 ap:0 ep:1 wo:d oos:0 uname -a Linux node04 2.6.18-164.11.1.el5 #1 SMP Wed Jan 6 13:26:04 EST 2010 x86_64 x86_64 x86_64 GNU/Linux haresources node03.companydomain.nl \ drbddisk \ Filesystem::/dev/drbd0::/data::ext3 \ mysql \ apache::/etc/httpd/conf/httpd.conf \ LVSSyncDaemonSwap::master \ monitor \ activemq \ tivoli-cluster \ MailTo::[email protected]::DRBDFailureDrisAcc \ MailTo::[email protected]::DRBDFailureDrisAcc \ 1.2.3.212 ha.cf debugfile /var/log/ha-debug logfile /var/log/ha-log keepalive 500ms deadtime 30 warntime 10 initdead 120 udpport 694 mcast eth0 225.0.0.3 694 1 0 mcast eth1 225.0.0.4 694 1 0 auto_failback off node node03.companydomain.nl node node04.companydomain.nl respawn hacluster /usr/lib64/heartbeat/dopd apiauth dopd gid=haclient uid=hacluster Thank you very much in advance, Ger Apeldoorn

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  • How to install SQL Server 2005 Configuration Manager without installing SQL Server Management Studio

    - by Arnold Zokas
    Hi, I need to configure SQL Server aliases on a public-facing production server. To do that, I need to install SQL Server Configuration Manager. I was not able to find a standalone installer for that, so I am having to install SQL Server 2005 Client Components. This approach is not ideal as we don't want to have SSMS on an public-facing production server. Is there a way to install SQL Server 2005 Configuration Manager without installing SQL Server Management Studio? Thanks, Arnold

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  • AuthSub target path prefix does not match the provided "next" URL

    - by dweebsonduty
    I am trying to use the Gcal API in PHP. I am using the ZEND framework function getAuthSubUrl($company) { $next = "http://$company.mysite.com"; $scope = 'http://www.google.com/calendar/feeds/'; $secure = false; $session = true; return (Zend_Gdata_AuthSub::getAuthSubTokenUri($next, $scope, $secure, $session)); } $authSubUrl = getAuthSubUrl(); echo "<a href=\"$authSubUrl\">login to your Google account"</a> I am not sure what I am doing wrong here. I am following the google example almost exactly. They do have $next = getCurrentUrl(); in their expample but I am getting undefined errors when I try that.

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  • Identify remote desktop client software and OS when user logs into Windows 2008 R2 Remote Desktop

    - by georged
    We would like to detect what devices & what programs users are using to connect to the Windows 2008 R2 Remote Desktop. In particular, we would like to have an ability to detect the remote devices such as iPads, iPhones & Androids, identify the software used and allow these connections only for certain users based on combination of the client OS + software. If it can be done in powershell to be run as part of the logon script, that'd be ideal.

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  • Can I ensure, using C#, that an X509Certificate was issued by a trusted authority?

    - by dommer
    If I use X509Certificate.CreateFromSignedFile to get the certificate used to sign a file, can I confirm that it was signed by a trusted authority - and isn't just a "self-signed" cert of some kind? I want to extract the "Subject" (company) name from the cert to ensure that an unmanaged DLL I'm using is unmolested (I can't checksum it as it's updated frequently and independently) and official. However, I'm concerned that a fake DLL could be signed with a "self-signed" cert and return the original company's name. So, I want to ensure the the cert was issued by Versign, Thwate or similar (anything installed on the cert repository on the machine will be fine). How can I do this, if at all, when using X509Certificate.CreateFromSignedFile? Or does it do this automatically (i.e. a "self-signed" cert will fail)?

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  • Setting up Elgg SMTP

    - by dde
    I am new to Elgg. I installed v1.7/ Right now, our newly registered users are not receiving activation email. I need to change SMTP settings and have Elgg use a relay server and not our company email server. The hosting company authorized me to use such relay. Now, I guess I have to edit some php file, somewhere, and type email server address. Can someone tell me how to change SMTP settings (and, perhaps those other settings you find in the initial setup page) ?

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  • How to index and search subversion repository

    - by Theo Briscoe
    I have access to a very large code base stored in a subversion repository. I would like to be able to perform Google type searched on the code base. I have done this before when I have access to the server by creating a network share and using Google desktop. I currently do not have access to this subversion server box. Any Ideas? Some more info The code base is company wide and large Don't want to download the entire code base for the entire business on my laptop My goal understand what code is available inside the company The code changes often Wondering if there are any tool that can search remote svn repositories?

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  • Database change management tools?

    - by zodeus
    We are currently in the process of solidifying a database change management process. We run MySql 5 running on RedHat 5. I have selected LiquiBase as the tool because it's open source and allows us to expand its functionality later if needed. It also seems to be one of the few free projects that are still active. Has anyone here had any experience using LiquiBase or other Db versioning tools? Company Background: We are an SaaS company providing a 7/24 hosted application. There are dozens of instances running different versions of the same database and we need a way to manage the deploy process as it's starting to get out of control. The databases have hundreds of tables and we typically do releases once every 3 months.

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  • Unknown Host error when attempting to connect to connect to Eclipse plugin repository

    - by BordrGuy108
    Hello, I am running Ubuntu 9.10 and I'm attempting to install a plugin for Eclipse 3.5 from a repository that my company created. This worked in the past on this linux box and also works just fine on my laptop which has Windows XP installed. The exact error message I'm getting in Eclipse is: Unknown Host: <location of repository> org.eclipse.equinox.internal.provisional.p2.core.ProvisionException Any ideas what might be causing something that used to work not to work anymore? Thanks! EDIT: Also, it might be useful to know that I can connect to other eclipse plugin repositories fine; it seems that only my company's internal one is the problem.

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  • I get EXC_BAD_ACCESS when MaxConcurrentOperationCount > 1

    - by kudorgyozo
    Hello i am using NSOperationQueue to download images in the background. I have created a custom NSOperation to download the images. I put the images in table cells. The problem is if I do [operationQueue setMaxConcurrentOperationCount: 10] and i scroll down several cells the program crashes with EXC_BAD_ACCESS. Every time it crashes at the same place in the table. There are 3 cells one after the other which are for the same company and have the same logo so basically it should download the images 3 times. Every other time it works fine. - (void) main { NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; NSURL *url = [[NSURL alloc] initWithString:self.imageURL]; debugLog(@"downloading image: %@", self.imageURL); //NSError *error = nil; NSData *data = [[NSData alloc] initWithContentsOfURL:url]; [url release]; UIImage *image = [[UIImage alloc] initWithData:data]; [data release]; if (image) { if (image.size.width != ICONWIDTH && image.size.height != ICONHEIGHT) { UIImage *resizedImage; CGSize itemSize = CGSizeMake(ICONWIDTH, ICONHEIGHT); UIGraphicsBeginImageContext(itemSize); CGRect imageRect = CGRectMake(0.0, 0.0, itemSize.width, itemSize.height); [image drawInRect:imageRect]; resizedImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); self.theImage = resizedImage; } else { self.theImage = image; } [image release]; } [delegate didFinishDownloadingImage: self]; [pool release]; } This is how i handle downloading the images. If i comment out [delegate didFinishDownloadingImage: self]; in the function above it doesn't crash but of course it is useless. -(void) didFinishDownloadingImage:(ImageDownloadOperation *) imageDownloader { [self performSelectorOnMainThread: @selector(handleDidFinishDownloadingImage:) withObject: imageDownloader waitUntilDone: FALSE]; } -(void) handleDidFinishDownloadingImage:(ImageDownloadOperation *)imageDownloadOperation { NSArray *visiblePaths = [self.myTableView indexPathsForVisibleRows]; CompanyImgDownloaderState *stateObject = (CompanyImgDownloaderState *)[imageDownloadOperation stateObject]; if ([visiblePaths containsObject: stateObject.indexPath]) { //debugLog(@"didFinishDownloadingImage %@ %@", imageDownloader.theImage); UITableViewCell *cell = [self.myTableView cellForRowAtIndexPath: stateObject.indexPath]; UIImageView *imageView = (UIImageView *)[cell viewWithTag: 1]; if (imageDownloadOperation.theImage) { imageView.image = imageDownloadOperation.theImage; stateObject.company.icon = imageDownloadOperation.theImage; } else { imageView.image = [(TestWebServiceAppDelegate *)[[UIApplication sharedApplication] delegate] getCylexIcon]; stateObject.company.icon = [(TestWebServiceAppDelegate *)[[UIApplication sharedApplication] delegate] getCylexIcon]; } } }

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  • How to customize a many-to-many inline model in django admin

    - by Jonathan
    I'm using the admin interface to view invoices and products. To make things easy, I've set the products as inline to invoices, so I will see the related products in the invoice's form. As you can see I'm using a many-to-many relationship. In models.py: class Product(models.Model): name = models.TextField() price = models.DecimalField(max_digits=10,decimal_places=2) class Invoice(models.Model): company = models.ForeignKey(Company) customer = models.ForeignKey(Customer) products = models.ManyToManyField(Product) In admin.py: class ProductInline(admin.StackedInline): model = Invoice.products.through class InvoiceAdmin(admin.ModelAdmin): inlines = [FilteredApartmentInline,] admin.site.register(Product, ProductAdmin) The problem is that django presents the products as a table of drop down menus (one per associated product). Each drop down contains all the products listed. So if I have 5000 products and 300 are associated with a certain invoice, django actually loads 300x5000 product names. Also the table is not aesthetic. How can I change it so that it'll just display the product's name in the inline table? Which form should I override, and how?

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  • Should I use WPF or ASP.NET for my next Web Application development?

    - by gap
    We have a web application that has been built using MySQL / PHP / Javascript+JQuery, with server-side HTML generation. The problem is that of the 10 software developers that work for the company, none are PHP experts (we're all .NET / C# developers). I need to make a recommendation to my management team on which technologies to use as the platform for the next generation of web application products. I want to leverage the .NET / C# expertise which the company has and is otherwise building, and so am inclined to recommend some Microsoft technologies. We don't want a client-side plugin, and we don't need flashy animations/multimedia, so I'm ruling out Silverlight. Is WPF ready for primetime? Is ASP.NET deprecated by WPF? How do I choose between these two technologies? Big Question, I know... I can refine it based on your comments if necessary. Thanks for taking the time.

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  • LINQ Expression not evaluating correctly

    - by WedTM
    I have the following LINQ expression that's not returning the appropriate response var query = from quote in db.Quotes where quote.QuoteStatus == "Estimating" || quote.QuoteStatus == "Rejected" from emp in db.Employees where emp.EmployeeID == quote.EmployeeID orderby quote.QuoteID descending select new { quote.QuoteID, quote.DateDue, Company = quote.Company.CompanyName, Attachments = quote.Attachments.Count, Employee = emp.FullName, Estimator = (quote.EstimatorID != null && quote.EstimatorID != String.Empty) ? db.Employees.Single (c => c.EmployeeID == quote.EstimatorID).FullName : "Unassigned", Status = quote.QuoteStatus, Priority = quote.Priority }; The problem lies in the Estimator = (quote.EstimatorID != null && quote.EstimatorID != String.Empty) ? db.Employees.Single(c => c.EmployeeID == quote.EstimatorID).FullName : "Unassigned" part. I NEVER get it to evalueate to "Unassigned", on the ones that are supposed to, it just returns null. Have I written this wrong?

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  • Visual Modeler in VS 6

    - by Yogi Yang 007
    Till date I have used only VB6 Professional for developing apps. But recently I have joined a company which owns VS 6 Enterprise (or some such version) I was just exploring what is available in VS 6 Ent. and I found Visual Modeler. The tutorial provided with it is not good enough. I was wondering if there is any detailed tutorial(s) for Visual Modeler? Is Visual Modeler a cut down version of Rational Rose? I have never used such a tool for developing apps. What are the benefits of developing apps like this? The document claims that one can speed up development and modifications of VB6 & VC++ 6 applications. How true is this claim? My company also has Ration Rose 6. Which is better Rational Rose 6 or Visual Modeler that comes with VS 6 Ent.?

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  • Build Procedure

    - by sarah xia
    Hi all, My company is putting auto build and deploy procedure in place. What we are doing now is checking out source code from svn and specify the source folder in Ant script. Is it the right way? Can we omit the exporting process and build directly from SVN? Another question is to do with versioning. At the moment, we are creating a tag whenever there is a release and then use the tag number to name the build product, which will be shipped to a client's site. I've done search on the Internet and here and it seems the correct way to name a product is like this: x.y.z.revision. However, our company is quite small and the client always want quick changes and releases. I would like to know what the drawbacks of only using tag number to name the product? And what would be the best approach for small companies like us? Thankyou, Sarah

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  • SQL - re-arrange a table via query

    - by abelenky
    I have a poorly designed table that I inherited. It looks like: User Field Value ------------------- 1 name Aaron 1 email [email protected] 1 phone 800-555-4545 2 name Mike 2 email [email protected] 2 phone 777-123-4567 (etc, etc) I would love to extract this data via a query in the more sensible format: User Name Email Phone ------------------------------------------- 1 Aaron [email protected] 800-555-4545 2 Mike [email protected] 777-123-4567 I'm a SQL novice, but have tried several queries with variations of Group By, all without anything even close to success. Is there a SQL technique to make this easy?

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  • Implication of variable context switching time

    - by Rob
    Hi, I know that constant switching time of the Linux scheduler was a big achievement. I was just asking myself the question what would be the implication of a non-constant switching time. The only obvious reason I can think of is real-time systems where we have to meet deadlines. There it is obviously no ideal if the switching time is "random". Are there any other good reasons that favour constant switching times? Many thanks, Rob

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  • Oracle Enterprise Linux or Red Hat Enterprise Linux?

    - by peturgretars
    I would highly appreciate hearing some opinions regarding the choice of Linux distribution when it comes to setting up an Oracle 11.2.0.3 RAC. We are about to install 2 node Oracle 11.2.0.3 RAC's in data centers A and B. Then we are going to have a standby in B for A and a standby in A for B using Data Guard in ASYNC transmit (long distance). Personally I have more experience with OEL and I know that for example Oracle Smart Flash Cache and zero patching downtime were only supported in OEL 5. I am not sure about OEL 6 vs RHEL 6 though. My question is, which Operating System should we go for and why, Oracle Enterprise Linux 5/6 or Red Hat Enterprise Linux 5/6? The hosting company is unfortunately not supporting OEL at the moment so if OEL is the choice then how would convince the hosting company to start using OEL and supporting it? Thanks so much!

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  • Help Understanding the Mork File Format

    - by Sumit Ghosh
    Hi, I have a name value pair in a Java HashMap and this in continuation to my earlier question - here NickName=,LastModifiedDate=4ac18267,FaxNumberType=,BirthMonth=,LastName=,HomePhone=,WorkCountry=,HomePhoneType=,PreferMailFormat=0,CellularNumber=,FamilyName=,[email protected],AnniversaryMonth=,HomeCity=,WorkState=,HomeCountry=,PhoneticFirstName=,PhoneticLastName=,HomeState=,WorkAddress=,WebPage1=,WebPage2=,HomeAddress2=,WorkZipCode=,_AimScreenName=,AnniversaryYear=,WorkPhoneType=,Notes=,WorkAddress2=,WorkPhone=,Custom3=,Custom4=,Custom1=,Custom2=,PagerNumber=,AnniversaryDay=,WorkCity=,AllowRemoteContent=0,CellularNumberType=,FaxNumber=,PopularityIndex=2,FirstName=,SpouseName=,CardType=,Department=,Company=,HomeAddress=,BirthDay=,SecondEmail=,RecordKey=1,DisplayName=,DefaultEmail=,DefaultAddress=,BirthYear=,Category=,PagerNumberType=,[email protected],JobTitle=,HomeZipCode=, NickName=,LastModifiedDate=0,FaxNumberType=,BirthMonth=,LastName=Ghosh,HomePhone=+504-9907-1342,WorkCountry=USA,HomePhoneType=,PreferMailFormat=2,CellularNumber=512-282-2512,FamilyName=,[email protected],AnniversaryMonth=,HomeCity=Siguatepeque,WorkState=TX,HomeCountry=Honduras,PhoneticFirstName=,PhoneticLastName=,HomeState=Comayagua,WorkAddress=9309 HeatherwoodDr,WebPage1=http://www.mpcsol.com,WebPage2=http://www.jesuslovesthelittlechildren.org,HomeAddress2=VillaAlicia,WorkZipCode=78748,_AimScreenName=rentaprogrammer,AnniversaryYear=,WorkPhoneType=,Notes=Some notes go here.,WorkAddress2=Apartment 1,WorkPhone=512-282-2509,Custom3=Faith,Custom4=Timothy,Custom1=Hannah,Custom2=John,PagerNumber=512-282-2511,AnniversaryDay=,WorkCity=Austin,AllowRemoteContent=1,CellularNumberType=,FaxNumber=512-282-2510,PopularityIndex=0,FirstName=Sumit,SpouseName=,CardType=,Department=Programming,Company=MPC Solutions,HomeAddress=Two Blocks Past Oxen Team,BirthDay=,[email protected],RecordKey=2,DisplayName=Sumit,DefaultEmail=,DefaultAddress=,BirthYear=,Category=,PagerNumberType=,[email protected],JobTitle=Programmer,HomeZipCode=NA, NickName=,LastModifiedDate=0,FaxNumberType=,BirthMonth=,LastName=,HomePhone=,WorkCountry=,HomePhoneType=,PreferMailFormat=0,CellularNumber=,FamilyName=,[email protected],AnniversaryMonth=,HomeCity=,WorkState=,HomeCountry=,PhoneticFirstName=,PhoneticLastName=,HomeState=,WorkAddress=,WebPage1=,WebPage2=,HomeAddress2=,WorkZipCode=,_AimScreenName=,AnniversaryYear=,WorkPhoneType=,Notes=,WorkAddress2=,WorkPhone=,Custom3=,Custom4=,Custom1=,Custom2=,PagerNumber=,AnniversaryDay=,WorkCity=,AllowRemoteContent=0,CellularNumberType=,FaxNumber=,PopularityIndex=0,FirstName=,SpouseName=,CardType=,Department=,Company=,HomeAddress=,BirthDay=,SecondEmail=,RecordKey=3,DisplayName=,DefaultEmail=,DefaultAddress=,BirthYear=,Category=,PagerNumberType=,[email protected],JobTitle=,HomeZipCode=, I want to write it to a Mork file , using the Mork file format, can someone tell me how to decode the name value pair to this format given below. <(A9=3)(81=)([email protected])(80=0)(85=2)(86=4ac18267)(83=1) (87=Sumit)(88=Ghosh)(89=Sumit)([email protected])(8B [email protected])(8C=512-282-2509)(8D=+504-9907-1342)(8E=512-282-2510) (8F=512-282-2511)(90=512-282-2512)(91=Two Blocks Past Oxen Team)(92 =Villa Alicia)(93=Siguatepeque)(94=Comayagua)(95=NA)(96=Honduras) (97=9309 Heatherwood Dr)(98=Apartment 1)(99=Austin)(9A=TX)(9B=78748) (9C=USA)(9D=Programmer)(9E=Programming)(9F=MPC Solutions)(A0 =rentaprogrammer)(A1=http://www.mpcsol.com)(A2 =http://www.jesuslovesthelittlechildren.org)(A3=Hannah)(A4=John) (A5=Faith)(A6=Timothy)(A7=Some notes go here.)(A8 [email protected])> {1:^80 {(k^C0:c)(s=9)} [1:^82(^BF=3)] [1(^83=)(^84=)(^85=)(^86=)(^87=)(^88=)(^89^82)(^8A^82)(^8B=)(^8C=) (^8D=)(^8E=0)(^8F=2)(^90=0)(^91=)(^92=)(^93=)(^94=)(^95=)(^96=) (^97=)(^98=)(^99=)(^9A=)(^9B=)(^9C=)(^9D=)(^9E=)(^9F=)(^A0=)(^A1=) (^A2=)(^A3=)(^A4=)(^A5=)(^A6=)(^A7=)(^A8=)(^A9=)(^AA=)(^AB=)(^AC=) (^AD=)(^AE=)(^AF=)(^B0=)(^B1=)(^B2=)(^B3=)(^B4=)(^B5=)(^B6=)(^B7=) (^B8=)(^B9=)(^BA=)(^BB=)(^BC^86)(^BD=1)] [2(^83^87)(^84^88)(^85=)(^86=)(^87^89)(^88=)(^89^8A)(^8A^8A)(^8B^8B) (^8C=)(^8D=)(^8E=2)(^8F=0)(^90=1)(^91^8C)(^92^8D)(^93^8E)(^94^8F) (^95^90)(^96=)(^97=)(^98=)(^99=)(^9A=)(^9B^91)(^9C^92)(^9D^93)(^9E^94) (^9F=NA)(^A0^96)(^A1^97)(^A2^98)(^A3^99)(^A4=TX)(^A5^9B)(^A6^9C) (^A7^9D)(^A8^9E)(^A9^9F)(^AA^A0)(^AB=)(^AC=)(^AD=)(^AE=)(^AF=)(^B0=) (^B1=)(^B2^A1)(^B3^A2)(^B4=)(^B5=)(^B6=)(^B7^A3)(^B8^A4)(^B9^A5) (^BA^A6)(^BB^A7)(^BC=0)(^BD=2)] [3(^83=)(^84=)(^85=)(^86=)(^87=)(^88=)(^89^A8)(^8A^A8)(^8B=)(^8C=) (^8D=)(^8E=0)(^8F=0)(^90=0)(^91=)(^92=)(^93=)(^94=)(^95=)(^96=) (^97=)(^98=)(^99=)(^9A=)(^9B=)(^9C=)(^9D=)(^9E=)(^9F=)(^A0=)(^A1=) (^A2=)(^A3=)(^A4=)(^A5=)(^A6=)(^A7=)(^A8=)(^A9=)(^AA=)(^AB=)(^AC=) (^AD=)(^AE=)(^AF=)(^B0=)(^B1=)(^B2=)(^B3=)(^B4=)(^B5=)(^B6=)(^B7=) (^B8=)(^B9=)(^BA=)(^BB=)(^BC=0)(^BD=3)]}

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