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  • Can I set ignore_dup_key on for a primary key?

    - by Mr. Flibble
    I have a two-column primary key on a table. I have attempted to alter it to set the ignore_dup_key to on with this command: ALTER INDEX PK_mypk on MyTable SET (IGNORE_DUP_KEY = ON); But I get this error: Cannot use index option ignore_dup_key to alter index 'PK_mypk' as it enforces a primary or unique constraint. How else should I set IGNORE_DUP_KEY to on?

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  • Alternative to singleton for unique resources

    - by user1320881
    I keep reading over and over again that one should avoid using singletons for various reasons. I'm wondering how to correctly handle a situation where a class represents a unique system resource. For example, a AudioOutput class using SDL. Since SDL_OpenAudio can only be open once at a time it makes no sense having more then one object of this type and it seems to me preventing accidentally making more then one object would actually be good. Just wondering what experienced programmers think about this, am i missing another option ?

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  • Is there anything wrong with having a few private methods exposing IQueryable<T> and all public meth

    - by Nate Bross
    I'm wondering if there is a better way to approach this problem. The objective is to reuse code. Let’s say that I have a Linq-To-SQL datacontext and I've written a "repository style" class that wraps up a lot of the methods I need and exposes IQueryables. (so far, no problem). Now, I'm building a service layer to sit on top of this repository, many of the service methods will be 1<-1 with repository methods, but some will not. I think a code sample will illustrate this better than words. public class ServiceLayer { MyClassDataContext context; IMyRepository rpo; public ServiceLayer(MyClassDataContext ctx) { context = ctx; rpo = new MyRepository(context); } private IQueryable<MyClass> ReadAllMyClass() { // pretend there is some complex business logic here // and maybe some filtering of the current users access to "all" // that I don't want to repeat in all of the public methods that access // MyClass objects. return rpo.ReadAllMyClass(); } public IEnumerable<MyClass> GetAllMyClass() { // call private IQueryable so we can do attional "in-database" processing return this.ReadAllMyClass(); } public IEnumerable<MyClass> GetActiveMyClass() { // call private IQueryable so we can do attional "in-database" processing // in this case a .Where() clause return this.ReadAllMyClass().Where(mc => mc.IsActive.Equals(true)); } #region "Something my class MAY need to do in the future" private IQueryable<MyOtherTable> ReadAllMyOtherTable() { // there could be additional constrains which define // "all" for the current user return context.MyOtherTable; } public IEnumerable<MyOtherTable> GetAllMyOtherTable() { return this.ReadAllMyOtherTable(); } public IEnumerable<MyOtherTable> GetInactiveOtherTable() { return this.ReadAllMyOtherTable.Where(ot => ot.IsActive.Equals(false)); } #endregion } This particular case is not the best illustration, since I could just call the repository directly in the GetActiveMyClass method, but let’s presume that my private IQueryable does some extra processing and business logic that I don't want to replicate in both of my public methods. Is that a bad way to attack an issue like this? I don't see it being so complex that it really warrants building a third class to sit between the repository and the service class, but I'd like to get your thoughts. For the sake of argument, lets presume two additional things. This service is going to be exposed through WCF and that each of these public IEnumerable methods will be calling a .Select(m => m.ToViewModel()) on each returned collection which will convert it to a POCO for serialization. The service will eventually need to expose some context.SomeOtherTable which wont be wrapped into the repository.

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  • Global variable in a recursive function how to keep it at zero?

    - by Grammin
    So if I have a recursive function with a global variable var_: int var_; void foo() { if(var_ == 3) return; else var_++; foo(); } and then I have a function that calls foo() so: void bar() { foo(); return; } what is the best way to set var_ =0 everytime foo is called thats not from within itself. I know I could just do: void bar() { var_ =0; foo(); return; } but I'm using the recursive function a lot and I don't want to call foo and forget to set var_=0 at a later date. Does anyone have any suggestions on how to solve this? Thanks, Josh

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  • MSSQL Server using multiple ID Numbers

    - by vincer
    I have an web application that creates printable forms, these forms have a unique number on them, the problem is I have 2 forms that separate numbers need to be created for them. ie) Form1- Numbered 2000000-2999999 Form2- Numbered 3000000-3999999 dbo.test2 - is my form information table Tsel - is my autoinc table for the 3000000 series numbers Tadv - is my autoinc table for the 2000000 series numbers What I have done is create 2 tables with just autoinc row (one for 2000000 series numbers and one for 3000000 series numbers), I then created a trigger to add a record to the coresponding table, read back the autoinc number and add it to my table that stores the form information including the just created autoinc number for the right series of forms. Although it does work, I'm concerned that the numbers will get messed up under load. I'm not sure the @@IDENTITY will always return the right value when many people are using the system. (I cannot have duplicates and I need to use the numbering form show above. Thanks for any help See code below. ** TRIGGER ** CREATE TRIGGER MAKEANID2 ON dbo.test2 AFTER INSERT AS SET NOCOUNT ON declare @someid int declare @someid2 int declare @startfrom int declare @test1 varchar(10) select @someid=@@IDENTITY select @test1 = (Select name1 from test2 where sysid = @someid ) if @test1 = 'select' begin insert into Tsel Default values select @someid2 = @@IDENTITY end if @test1 = 'adv' begin insert into Tadv Default values select @someid2 = @@IDENTITY end update test2 set name2=(@someid2) where sysid = @someid SET NOCOUNT OFF

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  • Ignoring (serious) errors to keep the program alive?

    - by SQuirreL bites
    One of the main things I wanted to achieve in my experimental programming language was: When errors occur (Syntax, Name, Type, etc.) keep the program running, no matter how serious or devastating it is. I know that this is probably very bad, but I just wanted something that doesn't kill itself on every error - I find it interesting what happens when a serious error occurs but the program continues. Does this "paradigm" have a name? I mean expect for How bad is it to do the above? Are there programs in use out there that just follow: "Hey, this is a fatal, unexpected error - but you know what? I don't care!"?

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  • Which of these methods provides for the fastest page loading?

    - by chromedude
    I am building a database in MySQL that will be accessed by PHP scripts. I have a table that is the activity stream. This includes everything that goes on on the website (following of many different things, liking, upvoting etc.). From this activity stream I am going to run an algorithm for each user depending on their activity and display relevant activity. Should I create another table that stores the activity for each user once the algorithm has been run on the activity or should I run the algorithm on the activity table every time the user accesses the site? UPDATE:(this is what is above except rephrased hopefully in an easier to understand way) I have a database table called activity. This table creates a new row every time an action is performed by a user on the website. Every time a user logs in I am going to run an algorithm on the new rows (since the users last login) in the table (activity) that apply to them. For example if the user is following a user who upvoted a post in the activity stream that post will be displayed when the user logs in. I want the ability for the user to be able to access previous content applying to them. Would it be easiest to create another table that saved the rows that have already been run over with the algorithm except attached to individual users names? (a row can apply to multiple different users)

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  • Adding behaviour to a set of classes

    - by devoured elysium
    I have defined an Event class: Event and all the following classes inherit from Event: SportEventType1 SportEventType2 SportEventType3 SportEventType4 Right now I will only have SportEvents but I don't know if in the future I'll want some other kind of events that doesn't even have anything to do with Sports. Later, I will want to draw some graphics with info taken from Events, and the drawing logic can be a bit complex. But, for the moment, I think I shouldn't think of how the drawing will be done and I believe that maybe it'd be better if that drawing part was not put as an integral part of the Event/SportEventX class chain. I am looking for solutions for this problem. I know I could just make Event have an instance variable(attribute, for the java crowds) pointing to something as an IDrawInterface, but that would make the Event class "assume" it will be later used for drawing. I would like to make the Event class oblivious to this if possible. Thanks!

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  • I built my rails app with sqlite and without specifying any db field sizes, Is my app now foobared for production?

    - by Tim Santeford
    I've been following a lot of good tutorials on building rails apps but I seem to be missing the whole specifying and validating db field sizes part. I love not needing to have to think about it when roughing out an app (I would have never done this with a PHP or ASP.net app). However, now that I'm ready to go to production, I think I might have done myself a disservice by not specifying field sizes as I went. My production db will be MySQL. What is the best practice here? Do I need to go through all of my migration files and specify sizes, update all the models with validation, and update all my form partial views with input max widths? or am I missing a critical step in my development process?

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  • Magic Method __set() on a Instanciated Object

    - by streetparade
    Ok i have a problem, sorry if i cant explaint it clear but the code speaks for its self. i have a class which generates objects from a given class name; Say we say the class is Modules: public function name($name) { $this->includeModule($name); try { $module = new ReflectionClass($name); $instance = $module->isInstantiable() ? $module->newInstance() : "Err"; $this->addDelegate($instance); } catch(Exception $e) { Modules::Name("Logger")->log($e->getMessage()); } return $this; } The AddDelegate Method: protected function addDelegate($delegate) { $this->aDelegates[] = $delegate; } The __call Method public function __call($methodName, $parameters) { $delegated = false; foreach ($this->aDelegates as $delegate) { if(class_exists(get_class($delegate))) { if(method_exists($delegate,$methodName)) { $method = new ReflectionMethod(get_class($delegate), $methodName); $function = array($delegate, $methodName); return call_user_func_array($function, $parameters); } } } The __get Method public function __get($property) { foreach($this->aDelegates as $delegate) { if ($delegate->$property !== false) { return $delegate->$property; } } } All this works fine expect the function __set public function __set($property,$value) { //print_r($this->aDelegates); foreach($this->aDelegates as $k=>$delegate) { //print_r($k); //print_r($delegate); if (property_exists($delegate, $property)) { $delegate->$property = $value; } } //$this->addDelegate($delegate); print_r($this->aDelegates); } class tester { public function __set($name,$value) { self::$module->name(self::$name)->__set($name,$value); } } Module::test("logger")->log("test"); // this logs, it works echo Module::test("logger")->path; //prints /home/bla/test/ this is also correct But i cant set any value to class log like this Module::tester("logger")->path ="/home/bla/test/log/"; The path property of class logger is public so its not a problem of protected or private property access. How can i solve this issue? I hope i could explain my problem clear.

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  • MVC alternatives: examples of MVA & AVC?

    - by Phillip Oldham
    I'm interested in learning about the alternative patterns to Model-View-Controller, specifically the Model-View-Adapter and Application-View-Controller patterns. Google results tend to be either a high-level overview or Java-based. Can anyone either provide, or point me to, an example of these patterns in either PHP, Python or JavaScript?

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  • When to update audit fields? DDD

    - by user676767
    I have a Meeting Object: Meeting{id, name, time, CreatedBy, UpdatedBy} and a MeetingAssignee{id, MeetingID, EmployeeId, CreatedBy, UpdatedBy) Meeting, as Aggregate root, has a method AssignEmployee. I was about to pass in the current user to the Meeting object as I call AssignEmployee, so that it can update its audit fields accordingly. But this doesn't seem right - is it? Obviously I can keep the audit fields public and change them later - perhaps at service level? What is everyone's else preferred method for updating these fields? Please note: We are not using Nhibernate, but a custom ORM which does not have anything automatic in place. Thanks.

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  • C#. Where struct methods code kept in memory?

    - by maxima120
    It is somewhat known where .NET keeps value types in memory (mostly in stack but could be in heap in certain circumstances etc)... My question is - where is the code of the struct? If I have say 16 byte of data fields in the struct and a massive computation method in it - I am presuming that 16 byte will be copied in stack and the method code is stored somewhere else and is shared for all instances of the struct. Are these presumptions correct?

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  • What difference between Web Apps & Descktop app shoud one keep in mind to model the system right?

    - by simple
    Sometimes it seems like some architectural techniques are not for the Web application I am building and then I just go and code =(, Though I really want to make a habit to architect system before moving to the code, as when I just code I endup writing some useless components which then I rewrite =(, So can you just point out some differences between web apps and desktop ones ?

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  • I need to create a contest....

    - by creocare
    I'm working on a contest where users vote for contestants. Each contestant will have a bio. I was wondering what would be the best way to approach this? Should I do this in php or javascript? Should I use a database to collect data? Should I use sqlite3? If I use sqlite3 how do i install that on my mac? I'm very new to all this but I'm a quick learner. Thanks for any advice.

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  • Add custom method to string object [closed]

    - by cru3l
    Possible Duplicate: Can I add custom methods/attributes to built-in Python types? In Ruby you can override any built-in object class with custom method, like this: class String def sayHello return self+" is saying hello!" end end puts 'JOHN'.downcase.sayHello # >>> 'john is saying hello!' How can i do that in python? Is there a normally way or just hacks?

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  • How much to put in a Repository class?

    - by chobo
    When using the repository pattern is it recommended to have one Repository class for each database table? Would I also map one service layer class to one repository class. I'm having a hard time trying to understand how much stuff one repository or service layer class should have. Thanks!

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  • Separation of business logic

    - by bruno
    When I was optimizing my architecture of our applications in our website, I came to a problem that I don't know the best solution for. Now at the moment we have a small dll based on this structure: Database <-> DAL <-> BLL the Dal uses Business Objects to pass to the BLL that will pass it to the applications that uses this dll. Only the BLL is public so any application that includes this dll, can see the bll. In the beginning, this was a good solution for our company. But when we are adding more and more applications on that Dll, the bigger the Bll is getting. Now we dont want that some applications can see Bll-logic from other applications. Now I don't know what the best solution is for that. The first thing I thought was, move and separate the bll to other dll's which i can include in my application. But then must the Dal be public, so the other dll's can get the data... and that I seems like a good solution. My other solution, is just to separate the bll in different namespaces, and just include only the namespaces you need in the applications. But in this solution, you can get directly access to other bll's if you want. So I'm asking for your opinions.

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  • How to handle request/response propagation up and down a widget hierarchy in a GUI app?

    - by fig-gnuton
    Given a GUI application where widgets can be composed of other widgets: If the user triggers an event resulting in a lower level widget needing data from a model, what's the cleanest way to be able to send that request to a controller (or the datastore itself)? And subsequently get the response back to that widget? Presumably one wouldn't want the controller or datastore to be a singleton directly available to all levels of widgets, or is this an acceptable use of singleton? Or should a top level controller be injected as a dependency through a widget hierarchy, as far down as the lowest level widget that might need that controller? Or a different approach entirely?

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