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• DevExpress Reporting Session Issue

  - by LeeHull

  This is pretty complicated so I will explain what is going on. I have created an ASP.NET website for displaying images, the way we use our images is, we have a database table that contains the URL where the images are located, however we recently started moving them from the filesystem, and storing them directly into the database as binary, but since we don't want to break older applications, we currently store them both places till they are all updated. Alright, the website I'm working on, is just a reporting website to display images by a date range, I have created an HTTPHandler to display the image, depending if they exist in the database as binary, if the row is DBNull, I just grab the URL from the other table instead, I just read the image, convert it into a byte[] and write it to the response, so it is interpreted as an image. I have created a page to display the report using DevExpress Reporting, I just query the report, save the dataset into a session, and the report reads the session to bind the report, i also have a picturebox in the report bound to "Handler.ashx?id=ImageID", this is because I am not binding a URL to the image, since it is a byte[] Also since there could be a report with 10000+ images, I am reading the dataset from the session inside the handler and just pulling out the image from the passed in ImageID, I am doing this to prevent connecting to the database each and every row. Now the strange thing is, Report loads fine.. data is loading, I have paging on the devexpress report viewer, it is loading the images fine, however here is the issue. When I print or export, I am not getting any images, I am debugged and found out the Session.Count is 0 when it tries to print or export, which is strange since there is more than just the dataset in the session. I have also added IRequiresSessionState to allow sessions in the handler, but the session count is still 0, I have changing the Handler to an aspx page, same issue. Any ideas or suggestions on logic changes, I'm all ears.. this is a very difficult situation since I have to display the images from database as a string AND byte[] since one can be URL and other be the image bytes, but I also can't slam the database on connection calls each row either. I have also reported the issue to DevExpress and they are clueless as well, since they don't dispose the session in the exporting process.

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• NHibernate unmapped class exception

  - by John Prideaux

  I am trying to implement a one-to-many relationship using NHibernate 2.1.2 but keep getting "Association references unmapped class" exceptions. I have verified that my hbm.xml files are embedded resource. Here are my classes and mappings. Any ideas? public class OrderStatus { public virtual decimal MainCommit { get; set; } public virtual decimal CommitNumber { get; set; } public virtual string InvoiceNumber { get; set; } public virtual string ShipTo { get; set; } public virtual string CustomerOrderNumber { get; set; } public virtual string Station { get; set; } public virtual DateTime RequestedShipDate { get; set; } public virtual decimal EstimatedValue { get; set; } public virtual decimal EstimatedWeight { get; set; } public virtual string Customer { get; set; } public virtual DateTime InvoiceDate { get; set; } public virtual ICollection<Promise> Promises { get; set; } } <class name="AladdinDb.Models.OrderStatus, AladdinDb" table="vorder_status"> <id name="CommitNumber" type="decimal" column="commit_no"> <generator class="assigned"> <param name="property"> Plan </param> </generator> </id> <property name="MainCommit" column="main_commit" type="decimal" /> <property name="InvoiceNumber" column="invoice_no" type="string" /> <property name="ShipTo" column="ship_to" type ="string"/> <property name="CustomerOrderNumber" column="cust_order_no" type="string" /> <property name="Station" column="station" type="string" /> <property name="RequestedShipDate" column="req_ship_date" type="DateTime" /> <property name="EstimatedValue" column="estimated_value" type="decimal"/> <property name="EstimatedWeight" column="estimated_weight" type="decimal" /> <property name="Customer" column="customer" type="string" /> <property name="InvoiceDate" column="invoice_date" /> <set name="Promises"> <key column="commit_no"></key> <one-to-many class="Promise" /> </set> </class> public class Promise { public virtual decimal CommitNumber { get; set; } public virtual DateTime PromiseDate { get; set; } public virtual string WhoAsked { get; set; } public virtual string WhoGave { get; set; } public virtual string Iffy { get; set; } } <class name="AladdinDb.Models.Promise, AladdinDb" table="promise"> <id name="CommitNumber" type="decimal" column="commit_no"> <generator class="assigned" /> </id> <property name="PromiseDate" column="promise_date" /> <property name="WhoAsked" column="who_asked" /> <property name="WhoGave" column="who_gave" /> <property name="Iffy" column="iffy" /> </class>

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• How to Access a decendant object's internal method in C#

  - by Giovanni Galbo

  I'm trying to access a method that is marked as internal in the parent class (in its own assembly) in an object that inherits from the same parent. Let me explain what I'm trying to do... I want to create Service classes that return IEnumberable with an underlying List to non-Service classes (e.g. the UI) and optionally return an IEnumerable with an underlying IQueryable to other services. I wrote some sample code to demonstrate what I'm trying to accomplish, shown below. The example is not real life, so please remember that when commenting. All services would inherit from something like this (only relevant code shown): public class ServiceBase<T> { protected readonly ObjectContext _context; protected string _setName = String.Empty; public ServiceBase(ObjectContext context) { _context = context; } public IEnumerable<T> GetAll() { return GetAll(false); } //These are not the correct access modifiers.. I want something //that is accessible to children classes AND between descendant classes internal protected IEnumerable<T> GetAll(bool returnQueryable) { var query = _context.CreateQuery<T>(GetSetName()); if(returnQueryable) { return query; } else { return query.ToList(); } } private string GetSetName() { //Some code... return _setName; } } Inherited services would look like this: public class EmployeeService : ServiceBase<Employees> { public EmployeeService(ObjectContext context) : base(context) { } } public class DepartmentService : ServiceBase<Departments> { private readonly EmployeeService _employeeService; public DepartmentService(ObjectContext context, EmployeeService employeeService) : base(context) { _employeeService = employeeService; } public IList<Departments> DoSomethingWithEmployees(string lastName) { //won't work because method with this signature is not visible to this class var emps = _employeeService.GetAll(true); //more code... } } Because the parent class lives is reusable, it would live in a different assembly than the child services. With GetAll(bool returnQueryable) being marked internal, the children would not be able to see each other's GetAll(bool) method, just the public GetAll() method. I know that I can add a new internal GetAll method to each service (or perhaps an intermediary parent class within the same assembly) so that each child service within the assembly can see each other's method; but it seems unnecessary since the functionality is already available in the parent class. For example: internal IEnumerable<Employees> GetAll(bool returnIQueryable) { return base.GetAll(returnIQueryable); } Essentially what I want is for services to be able to access other service methods as IQueryable so that they can further refine the uncommitted results, while everyone else gets plain old lists. Any ideas?

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• .NET: understanding web.config in asp.net

  - by mark smith

  Hi there, Does anyone know of a good link to explain how to use the web.config...... For example, i am using forms authentication... and i notice there is a system.web and then it closed /system.web and then below configuration there are additional location tags here is an example, if you ntoice there is an authentication mode=forms with authorization i presume this is the ROOT....... It is also self contained within a system.web .... Below this there are more location= with system.web tags.... I have never really understand what i am actually doing.. I have tried checkign the MSDN documentation but still i don't fully understand up.... Can anyone help? If you notice with my example.... everything is stored in 1 web.config... i thought the standard waas create a standard web.config and then create another web.config in the directory where i wish to protect it..??? <configuration> <system.web> <compilation debug="true" strict="false" explicit="true" targetFramework="4.0" /> <authentication mode="Forms"> <forms loginUrl="Login.aspx" defaultUrl="Login.aspx" cookieless="UseCookies" timeout="60"/> </authentication> <authorization> <allow users="*"/> </authorization> </system.web> <location path="Forms"> <system.web> <authorization> <deny users="?"/> <allow users="*"/> </authorization> </system.web> </location> <location path="Forms/Seguridad"> <system.web> <authorization> <allow roles="Administrador"/> <deny users="?"/> </authorization> </system.web> </location>

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• C# - Coding a nested stateflow diagram

  - by weberc2

  I have the following state diagram. I know how to make a simple state machine that transitions between non-nested states; however, I don't know how to transition between nested states. Could someone explain how to do this at an appropriately high level (i.e., you don't need to write the code for me--unless you're feeling particularly generous :P). State Diagram [EDIT: The bottom "A", "C", and "E" should be "B", "D", and "F" respectively; sorry!] What I know how to do public class MyState : State // State enumeration { public static MyState A = new MyState("State A"); public static MyState B = new MyState("State B"); public static MyState C = new MyState("State C"); public static MyState D = new MyState("State D"); public static MyState E = new MyState("State E"); public static MyState F = new MyState("State F"); public static MyState NEUT = new MyState("Neutral"); public static MyState P = new MyState("P"); protected MyState(string name) : base(name) { } } public class MyEvent : Event // Event enumeration { public static MyEvent X_POS = new MyEvent("X+"); public static MyEvent X_NEG = new MyEvent("X-"); public static MyEvent Y_POS = new MyEvent("Y+"); public static MyEvent Y_NEG = new MyEvent("Y-"); protected MyEvent(string name) : base(name) { } } public class MyStateMachine : StateMachine<MyState, MyEvent> // State Machine implementation { public MyStateMachine() : base(MyState.P) // MyState.P = initial state { // Set up the transition table // P this.addTransition(MYState.P, MyState.NEUT, MyEvent.Y_NEG); // NEUTRAL this.addTransition(MyState.NEUT, MyState.P, MyEvent.Y_POS); this.addTransition(MyState.NEUT, MyState.A, MyEvent.Y_NEG); this.addTransition(MyState.NEUT, MyState.B, MyEvent.Y_POS); this.addTransition(MyState.NEUT, MyState.C, MyEvent.Y_NEG); this.addTransition(MyState.NEUT, MyState.D, MyEvent.Y_POS); this.addTransition(MyState.NEUT, MyState.E, MyEvent.Y_NEG); this.addTransition(MyState.NEUT, MyState.F, MyEvent.Y_POS); // A this.addTransition(MyState.A, MyState.NEUT, MyEvent.Y_POS); // B this.addTransition(MyState.B, MyState.NEUT, MyEvent.Y_NEG); // C this.addTransition(MyState.C, MyState.NEUT, MyEvent.Y_POS); // D this.addTransition(MyState.D, MyState.NEUT, MyEvent.Y_NEG); // E this.addTransition(MyState.E, MyState.NEUT, MyEvent.Y_POS); // F this.addTransition(MyState.F, MyState.NEUT, MyEvent.Y_NEG); } public void move(MyEvent eevent) { try { this.moveNext(eevent); } catch (Exception e) { } } }

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• What'd be a good pattern on Doctrine to have multiple languages

  - by PERR0_HUNTER

  Hi! I have this challenge which consist in having a system that offers it's content in multiple languages, however a part of the data contained in the system is not translatable such as dates, ints and such. I mean if I have a content on the following YAML Corporativos: columns: nombre: type: string(254) notnull: true telefonos: type: string(500) email: type: string(254) webpage: type: string(254) CorporativosLang: columns: corporativo_id: type: integer(8) notnull: true lang: type: string(16) fixed: false ubicacion: type: string() fixed: false unsigned: false primary: false notnull: true autoincrement: false contacto: type: string() fixed: false unsigned: false primary: false notnull: true autoincrement: false tipo_de_hoteles: type: string(254) fixed: false unsigned: false primary: false notnull: true autoincrement: false paises: type: string() fixed: false unsigned: false primary: false notnull: true autoincrement: false relations: Corporativo: class: Corporativos local: corporativo_id foreign: id type: one foreignAlias: Data This would allow me to have different corporative offices, however the place of the corp, the contact and other things can be translate into a different language (lang) Now this code here would create me a brand new corporative office with 2 translations $corporativo = new Corporativos(); $corporativo->nombre = 'Duck Corp'; $corporativo->telefonos = '66303713333'; $corporativo->email = '[email protected]'; $corporativo->webpage = 'http://quack.com'; $corporativo->Data[0]->lang = 'en'; $corporativo->Data[0]->ubicacion = 'zomg'; $corporativo->Data[1]->lang = 'es'; $corporativo->Data[1]->ubicacion = 'zomg amigou'; the thing now is I don't know how to retrieve this data in a more friendly way, because if I'd like to access my Corporative info in english I'd had to run DQL for the corp and then another DQL for the specific translation in english, What I'd love to do is have my translatable fields available in the root so I could simply access them $corporativo = new Corporativos(); $corporativo->nombre = 'Duck Corp'; $corporativo->telefonos = '66303713333'; $corporativo->email = '[email protected]'; $corporativo->webpage = 'http://quack.com'; $corporativo->lang = 'en'; $corporativo->ubicacion = 'zomg'; this way the translatable fields would be mapped to the second table automatically. I hope I can explain my self clear :( any suggestions ?

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• iPhone UIImage upload to web service

  - by user347635

  Hi all, I worked on this for several hours today and I'm pretty close to a solution but clearly need some help from someone who's pulled this off. I'm trying to post an image to a web service from the iPhone. I'll post the code first then explain everything I've tried: NSData *imageData = UIImageJPEGRepresentation(barCodePic, .9); NSString *soapMsg = [NSString stringWithFormat: @"<?xml version=\"1.0\" encoding=\"utf-8\"?><soap:Envelope xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" xmlns:soap=\"http://schemas.xmlsoap.org/soap/envelope/\"><soap:Body><WriteImage xmlns=\"http://myserver/imagewebservice/\"><ImgIn>%@</ImgIn></WriteImage></soap:Body></soap:Envelope>", [NSData dataWithData:imageData] ]; NSURL *url = [NSURL URLWithString:@"http://myserver/imagewebservice/service1.asmx"]; NSMutableURLRequest *req = [NSMutableURLRequest requestWithURL:url]; NSString *msgLength = [NSString stringWithFormat:@"%d", [soapMsg length]]; [req addValue:@"text/xml; charset=utf-8" forHTTPHeaderField:@"Content-Type"]; [req addValue:@"http://myserver/imagewebservice/WriteImage" forHTTPHeaderField:@"SOAPAction"]; [req addValue:msgLength forHTTPHeaderField:@"Content-Length"]; [req setHTTPMethod:@"POST"]; [req setHTTPBody: [soapMsg dataUsingEncoding:NSUTF8StringEncoding]]; conn = [[NSURLConnection alloc] initWithRequest:req delegate:self]; if (conn) { webData = [[NSMutableData data] retain]; } First thing, this code works fine for anything but an image. The web service is running on my local network and I can change the source code at will and if I change the "ImgIn" parameter to a string and pass a string in, everything works fine, I get a return value no problem. So there are no connectivity issues at all, I'm able to call and get data from this web service on this server no problems. But I need to upload an image to this web service via the ImgIn parameter, so the above code is my best shot so far. I also have didReceiveResponse, didReceiveData, didFailWithError, etc all being handled. The above code fires off didRecieveResponse every time. However didReceiveData is never fired and it's like the web service itself never even runs. When I debug the web service itself, it runs and debugs fine when I use a string parameter, but with the image parameter, it never even debugs when I call it. It's almost like the ImgIn parameter is too long (it's huge when I output it to the screen) and the web service just chokes on it. I've read about having to encode to Base64 when using this method, but I can't find any good links on how that's done. If that's what I'm doing wrong, can you PLEASE provide code as to how to do this, not just "you need to use Base64", I'd really appreciate it as I can find almost nothing on how to implement this with an example. Other than that, I'm kind of lost, it seems like I'm doing everything else right. Please help! Thanks

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• PHP framework question

  - by iconiK

  I'm currently working on a browser-based MMO and have chosen the LAMP stack because of the extremely low cost to start with in production (versus Windows + IIS + ASP.NET/C# + SQL Server, even though I have MSDN Universal). However I will need a PHP framework for this as it's no easy task. I am not restricted by anything other than the ability to run on Linux, as I will use a dedicated cloud hosting solution (and a VMWare image for development) and can configure it as needed. In no specific order: It has to be easily scalable; this is crucial. If the game becomes a steady success it will eventually outgrow the server beyond what the host provides and would have to be moved to several load-balanced servers. It is crucial that this can be done with minimum effort. I do know this might require following strict conventions, so if you know of any for your suggested framework please explain what would be needed. It has to provide modules for all the core tasks: authentication, ACL, database access, MVC, and so on. One or two missing modules are fine, as long as they can easily be written and integrated. It should support internationalization. I think there is no excuse for any web framework not to provide means of translating the application and switching between languages without a lot of effort from the programmer. Must have very good community support and preferably commercial support as well. Yes, I do know QCodo/QCubed is so nice, but it is not mature enough for this task. Smooth AJAX support is required. Whether the framework comes with AJAX-capable widgets or has an easy way of adding AJAX is not relevant, as long as AJAX is easily doable. I plan to use jQuery + Dojo or one of them alone - not exactly sure. Auto-magically doing stuff when it improves readability and relieves a lot of effort would be especially nice if it is generally reliable and does not interfere with other requirements. This seems to be the case of CakePHP. I have read a lot of comparisons and I know it's a really hot debate. The general answer is "try and see for yourself what suits you". However, I can't say it is easy for this task and I'm calling for your experience with building applications with similar requirements. So far I'm tied up between Zend and CakePHP by the general criteria, however, all well-known frameworks offer the same functionality in some way or another with different approaches each with it's own advantages and disadvantages. Edits: I am kinda new to MVC, however, I am willing to learn it and I don't care if a framework is easier for those new to MVC. I have lots of time to learn MVC and any other architectures (or whatever they're called) you recommend. I will use Zend as a utility "framework", even though it's just a collection of libraries (some good ones though, as I have been told). Current PHP contenders are: CakePHP, Kohana, Zend alone.

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• Winform radiobutton data binding

  - by Rajarshi

  I am following the "Presentation Model" design pattern suggested by Martin Fowler for my GUI architecture in a Windows Forms project. "The essence of a Presentation Model is of a fully self-contained class that represents all the data and behavior of the UI window, but without any of the controls used to render that UI on the screen. A view then simply projects the state of the presentation model onto the glass...." - Martin Fowler Read more about this pattern at www.martinfowler.com/eaaDev/PresentationModel.html I am finding the concept very fluid and easy to understand except this one issue of data binding RadioButtons to properties on the Data/Domain object. Suposing I have a Windows Form with 3 radio buttons to depict some "Mode" options as - Auto Manual Import How can I use boolean properties on Data/Domain Objects to DataBind to these buttons? I have tried many ways but to no avail. For example I would like to code like - rbtnAutoMode.DataBindings.Add("Text", myBusinessObject, "IsAutoMode"); rbtnManualMode.DataBindings.Add("Text", myBusinessObject, "IsManualMode"); rbtnImportMode.DataBindings.Add("Text", myBusinessObject, "IsImportMode"); There should be a fourth property like "SelectedMode" on the data/domain object which at the end should depict a single value like "SelectedMode = Auto". I am trying to update this property when any of the "IsAutoMode", "IsManualMode" or "IsImportMode" is changed, e.g. through the property setters. I have INotifyPropertyChanged implemented on my data/domain object so, updating any data/domain object property automatically updates my UI controls, that's not an issue. There is a good example of binding 2 radio buttons here - http://stackoverflow.com/questions/344964/how-do-i-use-databinding-with-windows-forms-radio-buttons but I am missing the link while implementing the same with 3 buttons. I am having very erratic behaviors for the Radio Buttons. I hope I was able to explain reasonably. I am actually in a hurry and could not put a detailed code on post, but any help in this regard is appreciated. There is a simple solution to this issue by exposing a method like - public void SetMode(Modes mode) { this._selectedMode = mode; } which could be called from the "CheckedChanged" event of the Radio Buttons from the UI and would perfectly set the "SelectedMode" on the business object, but I need to stretch the limits to verify whether this can be done by DataBinding.

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• J: Self-reference in bubble sort tacit implementation

  - by Yasir Arsanukaev

  Hello people! Since I'm beginner in J I've decided to solve a simple task using this language, in particular implementing the bubblesort algorithm. I know it's not idiomatically to solve such kind of problem in functional languages, because it's naturally solved using array element transposition in imperative languages like C, rather than constructing modified list in declarative languages. However this is the code I've written: (((<./@(2&{.)), $:@((>./@(2&{.)),2&}.)) ^: (1<#)) ^: # Let's apply it to an array: (((<./@(2&{.)), $:@((>./@(2&{.)),2&}.)) ^: (1<#)) ^: # 5 3 8 7 2 2 3 5 7 8 The thing that confuses me is $: referring to the statement within the outermost parentheses. Help says that: $: denotes the longest verb that contains it. The other book (~ 300 KiB) says: 3+4 7 5*20 100 Symbols like + and * for plus and times in the above phrases are called verbs and represent functions. You may have more than one verb in a J phrase, in which case it is constructed like a sentence in simple English by reading from left to right, that is 4+6%2 means 4 added to whatever follows, namely 6 divided by 2. Let's rewrite my code snippet omitting outermost ()s: ((<./@(2&{.)), $:@((>./@(2&{.)),2&}.)) ^: (1<#) ^: # 5 3 8 7 2 2 3 5 7 8 Reuslts are the same. I couldn't explain myself why this works, why only ((<./@(2&{.)), $:@((>./@(2&{.)),2&}.)) ^: (1<#) is treated as the longest verb for $: but not the whole expression ((<./@(2&{.)), $:@((>./@(2&{.)),2&}.)) ^: (1<#) ^: # and not just (<./@(2&{.)), $:@((>./@(2&{.)),2&}.), because if ((<./@(2&{.)), $:@((>./@(2&{.)),2&}.)) ^: (1<#) is a verb, it should also form another verb after conjunction with #, i. e. one might treat the whole sentence (first snippet) as a verb. Probably there's some limit for the verb length limited by one conjunction. Look at the following code (from here): factorial =: (* factorial@<:) ^: (1&<) factorial 4 24 factorial within expression refers to the whole function, i. e. (* factorial@<:) ^: (1&<). Following this example I've used a function name instead of $:: bubblesort =: (((<./@(2&{.)), bubblesort@((>./@(2&{.)),2&}.)) ^: (1<#)) ^: # bubblesort 5 3 8 7 2 2 3 5 7 8 I expected bubblesort to refer to the whole function, but it doesn't seem true for me since the result is correct. Also I'd like to see other implementations if you have ones, even slightly refactored. Thanks.

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• LINQ to XML Cloning

  - by Sir Psycho

  Can anyone explain why the original address XElement street node changes? It looks like customer1 holds a reference to the address XElement but customer2 and customer3 have taken copies. Why did the original address change? (LINQPad example) var address = new XElement ("address", new XElement ("street", "Lawley St"), new XElement ("town", "North Beach") ); var customer1 = new XElement ("customer1", address); var customer2 = new XElement ("customer2", address); var customer3 = new XElement ("customer3", address); customer1.Element ("address").Element ("street").Value = "Another St"; Console.WriteLine (customer2.Element ("address").Element ("street").Value); Console.WriteLine (); address.Dump(); Console.WriteLine (); customer1.Dump(); Console.WriteLine (); customer2.Dump(); Console.WriteLine (); customer3.Dump(); OUTPUT Lawley St <address> <street>Another St</street> <town>North Beach</town> </address> <customer1> <address> <street>Another St</street> <town>North Beach</town> </address> </customer1> <customer2> <address> <street>Lawley St</street> <town>North Beach</town> </address> </customer2> <customer3> <address> <street>Lawley St</street> <town>North Beach</town> </address> </customer3>

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• Creating thousands of records in Rails

  - by willCosgrove

  Let me set the stage: My application deals with gift cards. When we create cards they have to have a unique string that the user can use to redeem it with. So when someone orders our gift cards, like a retailer, we need to make a lot of new card objects and store them in the DB. With that in mind, I'm trying to see how quickly I can have my application generate 100,000 Cards. Database expert, I am not, so I need someone to explain this little phenomena: When I create 1000 Cards, it takes 5 seconds. When I create 100,000 cards it should take 500 seconds right? Now I know what you're wanting to see, the card creation method I'm using, because the first assumption would be that it's getting slower because it's checking the uniqueness of a bunch of cards, more as it goes along. But I can show you my rake task desc "Creates cards for a retailer" task :order_cards, [:number_of_cards, :value, :retailer_name] => :environment do |t, args| t = Time.now puts "Searching for retailer" @retailer = Retailer.find_by_name(args[:retailer_name]) puts "Retailer found" puts "Generating codes" value = args[:value].to_i number_of_cards = args[:number_of_cards].to_i codes = [] top_off_codes(codes, number_of_cards) while codes != codes.uniq codes.uniq! top_off_codes(codes, number_of_cards) end stored_codes = Card.all.collect do |c| c.code end while codes != (codes - stored_codes) codes -= stored_codes top_off_codes(codes, number_of_cards) end puts "Codes are unique and generated" puts "Creating bundle" @bundle = @retailer.bundles.create!(:value => value) puts "Bundle created" puts "Creating cards" @bundle.transaction do codes.each do |code| @bundle.cards.create!(:code => code) end end puts "Cards generated in #{Time.now - t}s" end def top_off_codes(codes, intended_number) (intended_number - codes.size).times do codes << ReadableRandom.get(CODE_LENGTH) end end I'm using a gem called readable_random for the unique code. So if you read through all of that code, you'll see that it does all of it's uniqueness testing before it ever starts creating cards. It also writes status updates to the screen while it's running, and it always sits for a while at creating. Meanwhile it flies through the uniqueness tests. So my question to the stackoverflow community is: Why is my database slowing down as I add more cards? Why is this not a linear function in regards to time per card? I'm sure the answer is simple and I'm just a moron who knows nothing about data storage. And if anyone has any suggestions, how would you optimize this method, and how fast do you think you could get it to create 100,000 cards? (When I plotted out my times on a graph and did a quick curve fit to get my line formula, I calculated how long it would take to create 100,000 cards with my current code and it says 5.5 hours. That maybe completely wrong, I'm not sure. But if it stays on the line I curve fitted, it would be right around there.)

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• How should I provide access to this custom DAL?

  - by Casey

  I'm writing a custom DAL (VB.NET) for an ordering system project. I'd like to explain how it is coded now, and receive some alternate ideas to make coding against the DAL easier/more readable. The DAL is part of an n-tier (not n-layer) application, where each tier is in it's own assembly/DLL. The DAL consists of several classes that have specific behavior. For instance, there is an Order class that is responsible for retrieving and saving orders. Most of the classes have only two methods, a "Get" and a "Save," with multiple overloads for each. These classes are marked as Friend and are only visible to the DAL (which is in it's own assembly). In most cases, the DAL returns what I will call a "Data Object." This object is a class that contains only data and validation, and is located in a common assembly that both the BLL and DAL can read. To provide public access to the DAL, I currently have a static (module) class that has many shared members. A simplified version looks something like this: Public Class DAL Private Sub New End Sub Public Shared Function GetOrder(OrderID as String) as OrderData Dim OrderGetter as New OrderClass Return OrderGetter.GetOrder(OrderID) End Function End Class Friend Class OrderClass Friend Function GetOrder(OrderID as string) as OrderData End Function End Class The BLL would call for an order like this: DAL.GetOrder("123456") As you can imagine, this gets cumbersome very quickly. I'm mainly interested in structuring access to the DAL so that Intellisense is very intuitive. As it stands now, there are too many methods/functions in the DAL class with similar names. One idea I had is to break down the DAL into nested classes: Public Class DAL Private Sub New End Sub Public Class Orders Private Sub New End Sub Public Shared Function Get(OrderID as string) as OrderData End Function End Class End Class So the BLL would call like this: DAL.Orders.Get("12345") This cleans it up a bit, but it leaves a lot of classes that only have references to other classes, which I don't like for some reason. Without resorting to passing DB specific instructions (like where clauses) from BLL to DAL, what is the best or most common practice for providing a single point of access for the DAL?

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• Is SQL Server DRI (ON DELETE CASCADE) slow?

  - by Aaronaught

  I've been analyzing a recurring "bug report" (perf issue) in one of our systems related to a particularly slow delete operation. Long story short: It seems that the CASCADE DELETE keys were largely responsible, and I'd like to know (a) if this makes sense, and (b) why it's the case. We have a schema of, let's say, widgets, those being at the root of a large graph of related tables and related-to-related tables and so on. To be perfectly clear, deleting from this table is actively discouraged; it is the "nuclear option" and users are under no illusions to the contrary. Nevertheless, it sometimes just has to be done. The schema looks something like this: Widgets | +--- Anvils (1:1) | | | +--- AnvilTestData (1:N) | +--- WidgetHistory (1:N) | +--- WidgetHistoryDetails (1:N) Nothing too scary, really. A Widget can be different types, an Anvil is a special type, so that relationship is 1:1 (or more accurately 1:0..1). Then there's a large amount of data - perhaps thousands of rows of AnvilTestData per Anvil collected over time, dealing with hardness, corrosion, exact weight, hammer compatibility, usability issues, and impact tests with cartoon heads. Then every Widget has a long, boring history of various types of transactions - production, inventory moves, sales, defect investigations, RMAs, repairs, customer complaints, etc. There might be 10-20k details for a single widget, or none at all, depending on its age. So, unsurprisingly, there's a CASCADE DELETE relationship at every level here. If a Widget needs to be deleted, it means something's gone terribly wrong and we need to erase any records of that widget ever existing, including its history, test data, etc. Again, nuclear option. Relations are all indexed, statistics are up to date. Normal queries are fast. The system tends to hum along pretty smoothly for everything except deletes. Getting to the point here, finally, for various reasons we only allow deleting one widget at a time, so a delete statement would look like this: DELETE FROM Widgets WHERE WidgetID = @WidgetID Pretty simple, innocuous looking delete... that takes over 2 minutes to run, for a widget with no data! After slogging through execution plans I was finally able to pick out the AnvilTestData and WidgetHistoryDetails deletes as the sub-operations with the highest cost. So I experimented with turning off the CASCADE (but keeping the actual FK, just setting it to NO ACTION) and rewriting the script as something very much like the following: DECLARE @AnvilID int SELECT @AnvilID = AnvilID FROM Anvils WHERE WidgetID = @WidgetID DELETE FROM AnvilTestData WHERE AnvilID = @AnvilID DELETE FROM WidgetHistory WHERE HistoryID IN ( SELECT HistoryID FROM WidgetHistory WHERE WidgetID = @WidgetID) DELETE FROM Widgets WHERE WidgetID = @WidgetID Both of these "optimizations" resulted in significant speedups, each one shaving nearly a full minute off the execution time, so that the original 2-minute deletion now takes about 5-10 seconds - at least for new widgets, without much history or test data. Just to be absolutely clear, there is still a CASCADE from WidgetHistory to WidgetHistoryDetails, where the fanout is highest, I only removed the one originating from Widgets. Further "flattening" of the cascade relationships resulted in progressively less dramatic but still noticeable speedups, to the point where deleting a new widget was almost instantaneous once all of the cascade deletes to larger tables were removed and replaced with explicit deletes. I'm using DBCC DROPCLEANBUFFERS and DBCC FREEPROCCACHE before each test. I've disabled all triggers that might be causing further slowdowns (although those would show up in the execution plan anyway). And I'm testing against older widgets, too, and noticing a significant speedup there as well; deletes that used to take 5 minutes now take 20-40 seconds. Now I'm an ardent supporter of the "SELECT ain't broken" philosophy, but there just doesn't seem to be any logical explanation for this behaviour other than crushing, mind-boggling inefficiency of the CASCADE DELETE relationships. So, my questions are: Is this a known issue with DRI in SQL Server? (I couldn't seem to find any references to this sort of thing on Google or here in SO; I suspect the answer is no.) If not, is there another explanation for the behaviour I'm seeing? If it is a known issue, why is it an issue, and are there better workarounds I could be using?

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• Really "wow" them in the interview

  - by Juliet

  Let me put it to you this way: I'm a top-notch programmer, but a notoriously bad interviewee. I've flunked 3 interviews consecutively because I get so nervous that my voice tightens at least 2 octaves higher and I start visibly shaking -- mind you, I can handle whatever technical questions the interviewer throws at me in that state, but I think it looks bad to come off as a quivering, squeaky-voiced young woman during a job interview. I've just got the personality type of a shy computer programmer. No matter how technical I am, I'm going to get passed up in favor of a smooth talker. I have another interview coming up shortly, and I want to really impress the company. Here are my trouble spots: What can I do to be less nervous during my interview? I always get really excited when I hear I have a face-to-face interview, but get more and more anxious as D-Day the interview approaches. My employers wants me to explain what I used to do at my prior employment. I'm a very chatty person and tend to talk/squeak for 10 minutes at a time. How long or short should I time my answers? On that note, when I'm explaining what I did at prior jobs, what exactly is my interviewer looking for? At some point, my interviewer will ask "do you have any questions for me while you're here?" I should, but what kinds of questions should I ask to show that I'm interested in being employed? My interviewer always asks why I'm looking for a new job. The real reason is that my present salary is $27K/yr [Edit to add: and I've yet to get a raise since I started], and I want to make more money -- otherwise the work environment is fine. How do I sugarcoat "I want to make more money" into something that sounds nicer? I have only one prior programmer job, and I've worked there for 18 months, but I have the skill of someone with 4 to 6 years of experience. What can I say to compete against applicants with more work experience? I took a low-paying $27K/yr programming job just to get my foot in IT, and I've been trying to leverage that job as a stepping stone to better opportunities. I get interviews because I consistently out-score senior-level developers in aptitude tests, and my desired salary range is right in the ballpark of what most companies want to offer. Unfortunately, while I've been a programming as a hobby for 10 years and I'm geared to graduate with my BA in Comp Sci in May '09, employers see me as a junior-level programmer with no degree. I want to prove them wrong and get a job that matches my skill level. I'd appreciate any advice anyone has to offer, especially if they can help me get a better job in the process.

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• Converting to async,await using async targeting package

  - by e4rthdog

  I have this: private void BtnCheckClick(object sender, EventArgs e) { var a = txtLot.Text; var b = cmbMcu.SelectedItem.ToString(); var c = cmbLocn.SelectedItem.ToString(); btnCheck.BackColor = Color.Red; var task = Task.Factory.StartNew(() => Dal.GetLotAvailabilityF41021(a, b, c)); task.ContinueWith(t => { btnCheck.BackColor = Color.Transparent; lblDescriptionValue.Text = t.Result.Description; lblItemCodeValue.Text = t.Result.Code; lblQuantityValue.Text = t.Result.AvailableQuantity.ToString(); },TaskScheduler .FromCurrentSynchronizationContext() ); LotFocus(true); } and i followed J. Skeet's advice to move into async,await in my .NET 4.0 app. I converted into this: private async void BtnCheckClick(object sender, EventArgs e) { var a = txtLot.Text; var b = cmbMcu.SelectedItem.ToString(); var c = cmbLocn.SelectedItem.ToString(); btnCheck.BackColor = Color.Red; JDEItemLotAvailability itm = await Task.Factory.StartNew(() => Dal.GetLotAvailabilityF41021(a, b, c)); btnCheck.BackColor = Color.Transparent; lblDescriptionValue.Text = itm.Description; lblItemCodeValue.Text = itm.Code; lblQuantityValue.Text = itm.AvailableQuantity.ToString(); LotFocus(true); } It works fine. What confuses me is that i could do it without using Task but just the method of my Dal. But that means that i must have modified my Dal method, which is something i dont want? I would appreciate if someone would explain to me in "plain" words if what i did is optimal or not and why. Thanks P.s. My dal method public bool CheckLotExistF41021(string _lot, string _mcu, string _locn) { using (OleDbConnection con = new OleDbConnection(this.conString)) { OleDbCommand cmd = new OleDbCommand(); cmd.CommandText = "select lilotn from proddta.f41021 " + "where lilotn = ? and trim(limcu) = ? and lilocn= ?"; cmd.Parameters.AddWithValue("@lotn", _lot); cmd.Parameters.AddWithValue("@mcu", _mcu); cmd.Parameters.AddWithValue("@locn", _locn); cmd.Connection = con; con.Open(); OleDbDataReader rdr = cmd.ExecuteReader(); bool _retval = rdr.HasRows; rdr.Close(); con.Close(); return _retval; } }

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• Java: why is declaration not sufficient in interface?

  - by HH

  Big class contains Format-interfcase and Format-class. The Format-class contains the methods and the interface has the values of the fields. I could have the fields in the class Format but the goal is with Interface. So do I just create dummy-vars to get the errors away, design issue or something ELSE? KEY: Declaration VS Initialisation Explain by the terms, why you have to init in interface. What is the logic behind it? To which kind of problems it leads the use of interface? Sample Code having the init-interface-problem import java.util.*; import java.io.*; public class FormatBig { private static class Format implements Format { private static long getSize(File f){return f.length();} private static long getTime(File f){return f.lastModified();} private static boolean isFile(File f){if(f.isFile()){return true;}} private static boolean isBinary(File f){return Match.isBinary(f);} private static char getType(File f){return Match.getTypes(f);} private static String getPath(File f){return getNoErrPath(f);} //Java API: isHidden, --- SYSTEM DEPENDED: toURI, toURL Format(File f) { // PUZZLE 0: would Stack<Object> be easier? size=getSize(f); time=getTime(f); isfile=isFile(f); isBinary=isBinary(f); type=getType(f); path=getPath(f); //PUZZLE 1: how can simplify the assignment? values.push(size); values.push(time); values.push(isfile); values.push(isBinary); values.push(type); values.push(path); } } public static String getNoErrPath(File f) { try{return f.getCanonicalPath(); }catch(Exception e){e.printStackTrace();} } public static final interface Format { //ERR: IT REQUIRES "=" public long size; public long time; public boolean isFile=true; //ERROR goes away if I initialise wit DUMMY public boolean isBinary; public char type; public String path; Stack<Object> values=new Stack<Object>(); } public static void main(String[] args) { Format fm=new Format(new File(".")); for(Object o:values){System.out.println(o);} } }

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• PHP mysqli wrapper: passing by reference with __call() and call_user_func_array()

  - by Dave

  Hi everyone. I'm a long running fan of stackoverflow, first time poster. I'd love to see if someone can help me with this. Let me dig in with a little code, then I'll explain my problem. I have the following wrapper classes: class mysqli_wrapper { private static $mysqli_obj; function __construct() // Recycles the mysqli object { if (!isset(self::$mysqli_obj)) { self::$mysqli_obj = new mysqli(MYSQL_SERVER, MYSQL_USER, MYSQL_PASS, MYSQL_DBNAME); } } function __call($method, $args) { return call_user_func_array(array(self::$mysqli_obj, $method), $args); } function __get($para) { return self::$mysqli_obj->$para; } function prepare($query) // Overloaded, returns statement wrapper { return new mysqli_stmt_wrapper(self::$mysqli_obj, $query); } } class mysqli_stmt_wrapper { private $stmt_obj; function __construct($link, $query) { $this->stmt_obj = mysqli_prepare($link, $query); } function __call($method, $args) { return call_user_func_array(array($this->stmt_obj, $method), $args); } function __get($para) { return $this->stmt_obj->$para; } // Other methods will be added here } My problem is that when I call bind_result() on the mysqli_stmt_wrapper class, my variables don't seem to be passed by reference and nothing gets returned. To illustrate, if I run this section of code, I only get NULL's: $mysqli = new mysqli_wrapper; $stmt = $mysqli->prepare("SELECT cfg_key, cfg_value FROM config"); $stmt->execute(); $stmt->bind_result($cfg_key, $cfg_value); while ($stmt->fetch()) { var_dump($cfg_key); var_dump($cfg_value); } $stmt->close(); I also get a nice error from PHP which tells me: PHP Warning: Parameter 1 to mysqli_stmt::bind_result() expected to be a reference, value given in test.php on line 48 I've tried to overload the bind_param() function, but I can't figure out how to get a variable number of arguments by reference. func_get_args() doesn't seem to be able to help either. If I pass the variables by reference as in $stmt->bind_result(&$cfg_key, &$cfg_value) it should work, but this is deprecated behaviour and throws more errors. Does anyone have some ideas around this? Thanks so much for your time.

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• How to create a compiler in vb.net

  - by Cyclone

  Before answering this question, understand that I am not asking how to create my own programming language, I am asking how, using vb.net code, I can create a compiler for a language like vb.net itself. Essentially, the user inputs code, they get a .exe. By NO MEANS do I want to write my own language, as it seems other compiler related questions on here have asked. I also do not want to use the vb.net compiler itself, nor do I wish to duplicate the IDE. The exact purpose of what I wish to do is rather hard to explain, but all I need is a nudge in the right direction for writing a compiler (from scratch if possible) which can simply take input and create a .exe. I have opened .exe files as plain text before (my own programs) to see if I could derive some meaning from what I assumed would be human readable text, yet I was obviously sorely disappointed to see the random ascii, though it is understandable why this is all I found. I know that a .exe file is simply lines of code, being parsed by the computer it is on, but my question here really boils down to this: What code makes up a .exe? How could I go about making one in a plain text editor if I wanted to? (No, I do not want to do that, but if I understand the process my goals will be much easier to achieve.) What makes an executable file an executable file? Where does the logic of the code fit in? This is intended to be a programming question as opposed to a computer question, which is why I did not post it on SuperUser. I know plenty of information about the System.IO namespace, so I know how to create a file and write to it, I simply do not know what exactly I would be placing inside this file to get it to work as an executable file. I am sorry if this question is "confusing", "dumb", or "obvious", but I have not been able to find any information regarding the actual contents of an executable file anywhere. One of my google searches Something that looked promising EDIT: The second link here, while it looked good, was an utter fail. I am not going to waste hours of my time hitting keys and recording the results. "Use the "Alt" and the 3-digit combinations to create symbols that do not appear on the keyboard but that you need in the program." (step 4) How the heck do I know what symbols I need??? Thank you very much for your help, and my apologies if this question is a nooby or "bad" one. To sum this up simply: I want to create a program in vb.net that can compile code in a particular language to a single executable file. What methods exist that can allow me to do this, and if there are none, how can I go about writing my own from scratch?

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• Missing taglibrary in Netbeans Hibernate tutorial xhtml file?

  - by Christopher W. Allen-Poole

  I just finished the Netbeans introduction to Hibernate tutorial ( http://netbeans.org/kb/docs/web/hibernate-webapp.html#01 ) and I am getting the following error: "This page calls for XML namespace declared with prefix br but no taglibrary exists" Now, I have seen a similar question somewhere else: http://forums.sun.com/thread.jspa?threadID=5430327 but the answer is not listed there. Or, if it is, then I am clearly missing it -- line one of my index.xhtml file reads "http://www.w3.org/1999/xhtml". It also does not explain why, when I reload localhost:8080, the message disappears. Here is my index.xhtml file: <html xmlns="http://www.w3.org/1999/xhtml" xmlns:h="http://java.sun.com/jsf/html" xmlns:ui="http://java.sun.com/jsf/facelets" xmlns:f="http://java.sun.com/jsf/core"> <ui:composition template="./template.xhtml"> <ui:define name="body"> <h:form> <h:commandLink action="#{filmController.previous}" value="Previous #{filmController.pageSize}" rendered="#{filmController.hasPreviousPage}"/> <h:commandLink action="#{filmController.next}" value="Next #{filmController.pageSize}" rendered="#{filmController.hasNextPage}"/> <h:dataTable value="#{filmController.filmTitles}" var="item" border="0" cellpadding="2" cellspacing="0" rowClasses="jsfcrud_odd_row,jsfcrud_even_row" rules="all" style="border:solid 1px"> <h:column> <f:facet name="header"> <h:outputText value="Title"/> </f:facet> <h:outputText value="#{item.title}"/> </h:column> <h:column> <f:facet name="header"> <h:outputText value="Description"/> </f:facet> <h:outputText value="#{item.description}"/> </h:column> <h:column> <f:facet name="header"> <h:outputText value=" "/> </f:facet> <h:commandLink action="#{filmController.prepareView}" value="View"/> </h:column> </h:dataTable> <br/> </h:form> </ui:define> </ui:composition> </html>

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• SQL Server stored procedures - update column based on variable name..?

  - by ClarkeyBoy

  Hi, I have a data driven site with many stored procedures. What I want to eventually be able to do is to say something like: For Each @variable in sproc inputs UPDATE @TableName SET @variable.toString = @variable Next I would like it to be able to accept any number of arguments. It will basically loop through all of the inputs and update the column with the name of the variable with the value of the variable - for example column "Name" would be updated with the value of @Name. I would like to basically have one stored procedure for updating and one for creating. However to do this I will need to be able to convert the actual name of a variable, not the value, to a string. Question 1: Is it possible to do this in T-SQL, and if so how? Question 2: Are there any major drawbacks to using something like this (like performance or CPU usage)? I know if a value is not valid then it will only prevent the update involving that variable and any subsequent ones, but all the data is validated in the vb.net code anyway so will always be valid on submitting to the database, and I will ensure that only variables where the column exists are able to be submitted. Many thanks in advance, Regards, Richard Clarke Edit: I know about using SQL strings and the risk of SQL injection attacks - I studied this a bit in my dissertation a few weeks ago. Basically the website uses an object oriented architecture. There are many classes - for example Product - which have many "Attributes" (I created my own class called Attribute, which has properties such as DataField, Name and Value where DataField is used to get or update data, Name is displayed on the administration frontend when creating or updating a Product and the Value, which may be displayed on the customer frontend, is set by the administrator. DataField is the field I will be using in the "UPDATE Blah SET @Field = @Value". I know this is probably confusing but its really complicated to explain - I have a really good understanding of the entire system in my head but I cant put it into words easily. Basically the structure is set up such that no user will be able to change the value of DataField or Name, but they can change Value. I think if I were to use dynamic parameterised SQL strings there will therefore be no risk of SQL injection attacks. I mean basically loop through all the attributes so that it ends up like: UPDATE Products SET [Name] = '@Name', Description = '@Description', Display = @Display Then loop through all the attributes again and add the parameter values - this will have the same effect as using stored procedures, right?? I dont mind adding to the page load time since this is mainly going to affect the administration frontend, and will marginly affect the customer frontend.

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• $.ajax post to PHP mail() using jQuery doesn't work

  - by Vian Esterhuizen

  Hey, I looked around on SO and Google, but couldn't really find a solution. Could someone please explain to me why this doesn't work? This is my first time using AJAX to submit a form. $.ajax({ type: "POST", url: "<?php bloginfo('template_url'); ?>/email.php", data: dataString, success: function() { $('#contact_form').html("<div id='message'></div>"); $('#message').html("<h2>Contact Form Submitted!</h2>") .append("<p>We will be in touch soon.</p>") .hide() .fadeIn(1500, function() { $('#message').append("<img id='checkmark' src='images/check.png' />"); }); } }); and <?php $name=$_POST['name']; $email=$_POST['email']; $phone=$_POST['phone']; $subject=$_POST['subject']; $message=$_POST['message']; $quote=$_POST['quote']; $to="[email protected]"; $body="<p>From: ".$name." <".$email."><br />"; $body.="Phone: ".$phone."<br />"; $body.="Project: ".$subject."<br />"; $body.="Quote: ".$quote."</p>"; $body.="<p>Message:<br /> ".$message."</p>"; $headers = "MIME-Version: 1.0" . "\r\n"; $headers .= "Content-type: text/html; charset=iso-8859-1" . "\r\n"; $headers .= "From: ".$name."<".$email.">\r\n"; $headers .= "Reply-To: ".$name."<".$email.">\r\n"; $subject="New message from FloorShop.ca about \"".$subject."\""; @mail($to,$subject,$body,$headers); echo $name,$email,$phone,$subject,$message,$quote; ?

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• UIViewController not oreintating. Methods not called

  - by capple

  Greetings, This question does seem to be an ongoing saga in the world of iphone SDK... so heres my contribution... Had two separate projects from the same template... one semi-works, the other not at all... Please let me explain my steps... used this basic GL ES template //iphonedevelopment.blogspot.com/2008/12/opengl-project-template-for-xcode.html had to sort out some of the 'Release' configuration but otherwises has eveything I need to add orientation to a GL ES project. One my first project, did my stuff, then added these methods.... -(BOOL)shouldAutoRotateToInterfaceOrientation ..... -(void)willRotateToInterfaceOrientation .... -(void)didRotateFromInterfaceOrientation .... -(void)willAnimateRotationToInterfaceOrientation .... And understand what they do (or are trying to do in my case), the (BOOL)should... gets called once when the view controller is created, and returns 'YES'. But after that none of the other methods are called! So I started from scratch with a blank template (GL ES one from above)...and added minimum to support auto rotation. But this time none of the methods get called! So I investigated .... //developer.apple.com/iphone/library/qa/qa2010/qa1688.html as it said, I added the GLViewController.view first, then added the GLview as subviews of the application delegate. Nothing! Then found this //www.iphonedevsdk.com/forum/iphone-sdk-development/44993-how-determine-ipad-launch-orientation.html which states to enable orientation notifications [[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications]; and then subsequently disable them in the view controller... makes sense...did it, nothing... I think the notifications might be on by default though, since I didn't need to enable them in the first project, yet it still try to verify a orientation (i.e (BOOL)shouldAutoRotate... )... If any one could help me out it would be greatly appreciated as this issue is driving me insane. Thanks in advance. The code can be found here ... http://rapidshare.com/files/392053688/autoRotation.zip N.B These projects avoid nib/xib resources, would like to keep it that way if possible. P.S iPad device not out where I am so I cannot test on a device yet. Would be nice for it to work on the simulator.

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• Entity Framework in n-layered application - Lazy loading vs. Eager loading patterns

  - by Marconline

  Hi all. This questions doesn't let me sleep as it's since one year I'm trying to find a solution but... still nothing happened in my mind. Probably you can help me, because I think this is a very common issue. I've a n-layered application: presentation layer, business logic layer, model layer. Suppose for simplicity that my application contains, in the presentation layer, a form that allows a user to search for a customer. Now the user fills the filters through the UI and clicks a button. Something happens and the request arrives to presentation layer to a method like CustomerSearch(CustomerFilter myFilter). This business logic layer now keeps it simple: creates a query on the model and gets back results. Now the question: how do you face the problem of loading data? I mean business logic layer doesn't know that that particular method will be invoked just by that form. So I think that it doesn't know if the requesting form needs just the Customer objects back or the Customer objects with the linked Order entities. I try to explain better: our form just wants to list Customers searching by surname. It has nothing to do with orders. So the business logic query will be something like: (from c in ctx.CustomerSet where c.Name.Contains(strQry) select c).ToList(); now this is working correctly. Two days later your boss asks you to add a form that let you search for customers like the other and you need to show the total count of orders created by each customer. Now I'd like to reuse that query and add the piece of logic that attach (includes) orders and gets back that. How would you front this request? Here is the best (I think) idea I had since now. I'd like to hear from you: my CustomerSearch method in BLL doesn't create the query directly but passes through private extension methods that compose the ObjectQuery like: private ObjectQuery<Customer> SearchCustomers(this ObjectQuery<Customer> qry, CustomerFilter myFilter) and private ObjectQuery<Customer> IncludeOrders(this ObjectQuery<Customer> qry) but this doesn't convince me as it seems too complex. Thanks, Marco

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• Evaluation of CTEs in SQL Server 2005

  - by Jammer

  I have a question about how MS SQL evaluates functions inside CTEs. A couple of searches didn't turn up any results related to this issue, but I apologize if this is common knowledge and I'm just behind the curve. It wouldn't be the first time :-) This query is a simplified (and obviously less dynamic) version of what I'm actually doing, but it does exhibit the problem I'm experiencing. It looks like this: CREATE TABLE #EmployeePool(EmployeeID int, EmployeeRank int); INSERT INTO #EmployeePool(EmployeeID, EmployeeRank) SELECT 42, 1 UNION ALL SELECT 43, 2; DECLARE @NumEmployees int; SELECT @NumEmployees = COUNT(*) FROM #EmployeePool; WITH RandomizedCustomers AS ( SELECT CAST(c.Criteria AS int) AS CustomerID, dbo.fnUtil_Random(@NumEmployees) AS RandomRank FROM dbo.fnUtil_ParseCriteria(@CustomerIDs, 'int') c) SELECT rc.CustomerID, ep.EmployeeID FROM RandomizedCustomers rc JOIN #EmployeePool ep ON ep.EmployeeRank = rc.RandomRank; DROP TABLE #EmployeePool; The following can be assumed about all executions of the above: The result of dbo.fnUtil_Random() is always an int value greater than zero and less than or equal to the argument passed in. Since it's being called above with @NumEmployees which has the value 2, this function always evaluates to 1 or 2. The result of dbo.fnUtil_ParseCriteria(@CustomerIDs, 'int') produces a one-column, one-row table that contains a sql_variant with a base type of 'int' that has the value 219935. Given the above assumptions, it makes sense (to me, anyway) that the result of the expression above should always produce a two-column table containing one record - CustomerID and an EmployeeID. The CustomerID should always be the int value 219935, and the EmployeeID should be either 42 or 43. However, this is not always the case. Sometimes I get the expected single record. Other times I get two records (one for each EmployeeID), and still others I get no records. However, if I replace the RandomizedCustomers CTE with a true temp table, the problem vanishes completely. Every time I think I have an explanation for this behavior, it turns out to not make sense or be impossible, so I literally cannot explain why this would happen. Since the problem does not happen when I replace the CTE with a temp table, I can only assume it has something to do with the functions inside CTEs are evaluated during joins to that CTE. Do any of you have any theories?

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