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  • How to model my database when using entity framework 4?

    - by Junior Ewing
    Trying to wrap my head around the best approach in modelling a database when we are using Entity Framework 4 as the ORM layer. We are going to use asp.net mvc 2 for the application. Is it worth trying to model using the class diagram modeller that comes with Visual Studio 2010 where you graphically configure your models into the EDMX file and then generate out the database structure? I have run into a bunch of non trivial issues and for complex many to many mappings or multi primary key entities the answer is not that obvious even after poking around a while with the tools. I figure its easy at this point to give up and start modelling the DB using real, working DB modelling tools and then try to generate out the EDMX from the database, rather than trying to do the model first approach.

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  • Autmatically create table on MySQL server based on date?

    - by Anthony
    Is there an equivalent to cron for MySQL? I have a PHP script that queries a table based on the month and year, like: SELECT * FROM data_2010_1 What I have been doing until now is, every time the script executes it does a query for the table, and if it exists, does the work, if it doesn't it creates the table. I was wondering if I can just set something up on the MySQL server itself that will create the table (based on a default table) at the stroke of midnight on the first of the month. Update Based on the comments I've gotten, I'm thinking this isn't the best way to achieve my goal. So here's two more questions: If I have a table with thousands of rows added monthly, is this potentially a drag on resources? If so, what is the best way to partition this table, since the above is verboten? What are the potential problems with my home-grown method I originally thought up?

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  • How can I create XSD files from M documents?

    - by Andrew Matthews
    Does anyone know of a nice way to: produce XSD documents from an OSLO model consume conformant XML documents using that model and add directly into the DB created from the model? I can't see any obvious way from the current documentation, but I'm a newcomer, so I may have missed something. Thanks.

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  • c# object instantiation

    - by user1112111
    What's the difference between: Object o = new Object(); o.foo(); and new Object().foo(); (assuming I do not need the reference afterwards) ? Are there any reasons for using one instead of the other one (e.g. memory usage) ?

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  • Core Data: Deleting causes 'NSObjectInaccessibleException' from NSOperation with a reference to a deleted object

    - by Bryan Irace
    My application has NSOperation subclasses that fetch and operate on managed objects. My application also periodically purges rows from the database, which can result in the following race condition: An background operation fetches a bunch of objects (from a thread-specific context). It will iterate over these objects and do something with their properties. A bunch of rows are deleted in the main managed object context. The background operation accesses a property on an object that was deleted from the main context. This results in an 'NSObjectInaccessibleException', reason: 'CoreData could not fulfill a fault' Ideally, the objects that are fetched by the NSOperation can be operated on even if one is deleted in the main context. The best way I can think to achieve this is either to: Call [request setReturnsObjectsAsFaults:NO] to ensure that Core Data won't try to fulfill a fault for an object that no longer exists in the main context. The problem here is I may need to access the object's relationships, which (to my understanding) will still be faulted. Iterate through the managed objects up front and copy the properties I will need into separate non-managed objects. The problem here is that (I think) I will need to synchronize/lock this part, in case an object is deleted in the main context before I can finish copying. Am I missing something obvious? It doesn't seem like what I'm trying to accomplish is too out of the ordinary. Thanks for your help.

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  • Where do I put javaassist code?

    - by DutrowLLC
    I have an application running on google app engine. I'm using restlets and I have a couple of layers set up including the restlet layer, the model layer, the business layer, and the data layer. I'm attempting to use javaassist to modify some classes, but I'm unsure where to actually put the code. I tried to put the code in the static initialization block: public class Person { String firstName; String getFirstName(){return null;} static{ ClassPool pool = ClassPool.getDefault(); try { CtClass CtPerson = pool.get("Person"); CtMethod CtGetFirstName = CtPerson.getDeclaredMethod("GetFirstName"); CtGetFirstName.setBody("return firstName;"); CtPerson.toClass(); } catch (Exception e) { e.printStackTrace(); } } } ...but that resulted in this error: javassist.CannotCompileException:.....attempted duplicate class definition...". I guess it makes sense that I can't edit the class file in the middle of its generation. I know the code works because I was able to run it correctly by simply putting it in a location that would run when I sent the program a command. (accessed a Restlet resource). The code ran fine if an instance of the class had not already been instantiated, however once I instantiated an instance of the affected class, the javaassist code failed. I assume I need to put this code somewhere that it will only run either: once after the program starts, directly before a class is instantiated for the first time, or even better, during compile time.

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  • Get Excel.Application object from Process or hwnd in .NET

    - by Abiel
    In C# I am trying to get an instance of an Excel.Application object from a Process object. This seems like it should be really simple yet I cannot figure it out and cannot find an example. To repeat, I have a System.Diagnostics.Process object that I know refers to a running Excel instance. I now need to recover a Microsoft.Office.Interop.Excel.Application object that refers to the process so that I can go about manipulating the Excel application from C#. In case it makes it any simpler, I also have the HWND id and window text associated with the active Excel window. Thanks.

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  • How to "uninstantiate" an object?

    - by Mark
    I wrote a function in Python: def instantiate(c): if inspect.isclass(c): return c() elif isinstance(c, object): return c else: raise Exception, '%s is not an object or class.' % c Now I want to do the opposite: get the class from an already instantiated object so that I can re-instantiate it with different parameters. How can I do that?

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  • how to store/model users/faceboook users/linkedin users, etc, with ActiveRecord?

    - by crankharder
    My app has "normal" users: those which come through a typical signup page facebook(FB) users: those which come from Facebook connect "FB-normal" users: a user that can log with both email/password * FB connect Further, there's the a slew of other openID-ish login methods (I don't think openID itself will be acceptable since it doesn't link up the accounts and allow the 3rd party specific features (posting to twitter, adding a FB post, etc etc)) So, how do I model this? Right now we have User class with #facebook_user? defined -- but it gets messy with the "FB-normal" users - plus all the validations become very tricky and hard to interpret. Also, there are methods like #deliver_password_reset! which make no sense in the context for facebook-only users. (this is lame) I've thought out STI (User::Facebook, User::Normal, User::FBNormal, etc.) This makes validations super slick, but it doesn't scale to other connection types, and all the permutations between them... User::FacebookLinkedInNormal(wtf?) Doing this with a bunch of modules I think would suck a lot. Any other ideas?

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  • Can I bind multiple forms to a single model using the default model binder?

    - by MedicineMan
    I have a complex page with several forms on it. The page is divided into sections, and each section has a continue button on it. The page is bound to a pageViewModel, each section addresses a different set of properties on the model. The continue button makes an ajax call to the controller, and the model binder binds it appropriately to the appropriate sections of the model. The section is refreshed appropriately. Finally, I would like to have a save button at the bottom of the page that takes all the forms, and binds all of the forms to the model. The model, at this point has all of the properties filled out, and can be processed accordingly. Can I accomplish this by some ASP MVC magic?

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  • Data Model Evolution

    - by redleafong
    Hey guys, When writing code I am seeing requirements to change data models (e.g. adding/changing/removing data members from a class). When these data models belong to an interface, it seems difficult to change without breaking the existing client codes. So I am wondering if there is any best practice of designing interfaces/data models in a way to minimize the impact during evolution. The closest thing I can find from google is data contract versioning. But that seems to be a .net specific topic. I am wondering if the same practice applies to the Java world, or there is a different or generic way to deal with data model evolution. Thanks

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  • Grasp Controller, Does it really need a UI to exist?

    - by dbones
    I have a Domain model which can be in multiple states, and if these states go out of a given range it the domain should automatically react. For example I have a Car which is made of multiple things which have measurements the Engine - Rev counter and Temperature the Fuel Tank - capacity Is is plaseable to have a CarStateController, which observses the engine and the tank, and if these states go out of range IE the engine temperature goes above range, turn the engine fan on?? There is no UI, (you could argue it would show a light on the dash board, but for this case it does not) is this a valid use of a GRASP controller pattern? if not what is this CarStateController Called? Or have I completely missed the point and this should be the State Pattern?

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  • How to check if two records have a self-referencing relation?

    - by Machine
    Consider the following schema with users and their collegues (friends): Users User: columns: user_id: name: user_id as userId type: integer(8) unsigned: 1 primary: true autoincrement: true first_name: name: first_name as firstName type: string(45) notnull: true last_name: name: last_name as lastName type: string(45) notnull: true email: type: string(45) notnull: true unique: true relations: Collegues: class: User local: invitor foreign: invitee refClass: CollegueStatus equal: true onDelete: CASCADE onUpdate: CASCADE Join table: CollegueStatus: columns: invitor: type: integer(8) unsigned: 1 primary: true invitee: type: integer(8) unsigned: 1 primary: true status: type: enum(8) values: [pending, accepted, denied] default: pending notnull: true Now, let's say I two records, one for the user making a HTTP request (the logged in user), and one record for a user he wants to send a message to. I want to check if these users are collegues. Questions: Does Doctrine have any pre-build functionality to check if two records with with self-relations are related? If not, how would you write a method to check this? Where would you put said method? (In the User-class, UserTable-class etc) I could probably do something like this: public function (User $user1, User $user2) { // Ensure we load collegues if $user1 was fetched with DQL that // doesn't load this relation $collegues = $user1->get('Collegues'); $areCollegues = false; foreach($collegues as $collegue) { if($collegue['userId'] === $user2['userId']) { $areCollegues = true; break; } } return $areCollegues; } But this looks a neither efficient nor pretty. I just feel that it should be solved already for self-referencing relations to be nice to use.

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  • Application Design: Single vs. Multiple Hits to the DB

    - by shyneman
    I'm building a service that performs a set of configured activities based on the type of request that it receives. Each activity involves going to the database and retrieving/updating some kind of information. The logic for each activity can be generalized and re-used across different request types. The activities may need to participate in a transaction for the duration of the servicing the request. One option, I'm considering is having each activity maintain its own access to DAL/database. This fully encapsulates the activity into a stand-alone re-usable piece, but hitting the database multiple times for one request doesn't seem like a viable option. I don't really know how to easily implement the concept of a transaction across the multiple activities here either. The second option is to encapsulate ALL the activities into one big activity and hit the database once. But this does not allow re-use and configuration of these activities for different requests. Does anyone have any suggestions and input about what should be the best way to approach my problem? Thanks for any help.

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  • c#3.5 Deserialization error - object reference not set

    - by BBR
    I am trying to deserialize an xml string in c#3.5, the code below does work in c# 4.0. When I try to run in the code in c#3.5 I get an Object reference not set to an instance of an object exception when the code tries in initialize the XmlSerializer. Any help would be appreciated. string xml = "<boolean xmlns=\"http://schemas.microsoft.com/2003/10/serialization/\">false</boolean>"; var xSerializer = new XmlSerializer(typeof(bool), null, null, new XmlRootAttribute("boolean"), "http://schemas.microsoft.com/2003/10/serialization/"); using (var sr = new StringReader(xml)) using (var xr = XmlReader.Create(sr)) { var y = xSerializer.Deserialize(xr); } System.NullReferenceException was unhandled Message="Object reference not set to an instance of an object." Source="System.Xml" StackTrace: at System.Xml.Serialization.XmlSerializer..ctor(Type type, XmlAttributeOverrides overrides, Type[] extraTypes, XmlRootAttribute root, String defaultNamespace, String location, Evidence evidence) at System.Xml.Serialization.XmlSerializer..ctor(Type type, XmlAttributeOverrides overrides, Type[] extraTypes, XmlRootAttribute root, String defaultNamespace) .... at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args) at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly() at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ThreadHelper.ThreadStart() InnerException:

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  • Cannot export a fusionchart with 'Embedding Charts Using <OBJECT>/<EMBED> Tags'

    - by zoom_pat277
    I am trying to export a fusion chart created using 'Embedding Charts Using / Tags'. Export works just perfect with the right click (on the chart) and chose a pdf to export. But I am not able to make this work via javascript. I have a button outside the chart which upon clicking calls the function below function myexport() { var object = getChartFromId('myChartid'); if( object.hasRendered() ) object.exportChart({exportFormat: 'PDF'}); } the object above returned is null and this fails on the next line here is the full prototype <html> <head> <title>My Chart</title> <script type="text/javascript" src="fusionCharts.debug.js"></script> <script type="text/javascript" src="fusionChartsExportComponent.js"></script> <script type="text/javascript"> function ExportMyChart() { var cObject = getChartFromId('Column3D'); if( cObject.hasRendered() ) cObject.exportChart({exportFormat: 'PDF'}); } </script> </head> <body> <object width="400" height="400" id="Column3D" classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" codebase="http://fpdownload.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=8,0,0,0" > <param name="testname" value="Column3D.swf" /> <param name="FlashVars" value="&dataURL=testData.xml&chartWidth=400&chartHeight=300&DOMId=myChart1&registerWithJS=1&debugMode=0"> <param name="quality" value="high" /> <embed src="Column3D.swf" flashVars="&dataURL=testData.xml&chartWidth=400&chartHeight=300&DOMId=myChart1&registerWithJS=1&debugMode=0" width="400" height="300" name="Column3D" quality="high" type="application/x-shockwave-flash" pluginspage="http://www.macromedia.com/go/getflashplayer" /> </object> <!-- We also create a DIV to contain the FusionCharts client-side exporter component --> <div id="holderDiv" align="center">FusionCharts Export Handler Component</div> <script type="text/javascript"> var myExportComponent = new FusionChartsExportObject("testExporter1", "FCExporter.swf"); //Render the exporter SWF in our DIV fcexpDiv myExportComponent.Render("holderDiv"); </script> <input type="button" value="Export My Chart" onclick="ExportMyChart()" />

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  • C++ return a "NULL" object if search result not found

    - by aduric
    I'm pretty new to C++ so I tend to design with a lot of Java-isms while I'm learning. Anyway, in Java, if I had class with a 'search' method that would return an object T from a Collection< T that matched a specific parameter, I would return that object and if the object was not found in the collection, I would return a NULL. Then in my calling function I would just check if(T != NULL) { ... } In C++, I'm finding out that I can't return a NULL if the object doesn't exist. I just want to return an 'indicator' of type T that notifies the calling function that no object has been found. I don't want to throw an exception because it's not really an exceptional circumstance. class Node { .... Attr& getAttribute(const string& attribute_name) const { //search collection //if found at i return attributes[i]; //if not found return NULL; } private: vector<Attr> attributes; }

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  • In what package should a "Settings" class be?

    - by Tom
    I've in the middle of building an application but found myself too easily creating new packages without keeping the project's structure in mind. Now, I'm trying to redo the whole project structure on paper first. I am using a Settings class with public properties, accessed as settings for several other classes around the project. Now, since this Settings class applies for the whole project, I am unsure if it should be packaged and if so, in what kind of package should it exist? Or should it be in the root (the default package) with the main application class? I've been thinking about putting it in my utils package, then again I don't think it really is an utlity. Any strategies on how to decide on such package structure for example for a Settings class?

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  • how to write a constructor...

    - by Nima
    is that correct to write a constructor like this? class A { A::A(const A& a) { .... } }; if yes, then is it correct to invoke it like this: A* other; ... A* instance = new A(*(other)); if not, what do you suggest? Thanks

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  • getting aspect related information reg

    - by GowthamanSS
    Suppose i have these structure as class ss { public void createfile() { StreamWriter sw= new StreamWriter("d:/test.txt"); } } i need to do aspect where ever i use StreamWriter? as for as consideration i already used the below code as [assembly: MyAspect(AttributeTargetAssembly="mscorlib", AttributeTargetTypes="System.IO.File", AttributeTargetMembers="Create"] for file.create method .. it works fine .. Is there any way to solve this problem ... waiting for your response

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  • Domain Model and Contracts

    - by devoured elysium
    I am modelling a DVD Rental Store: A Client gives its clientNumber to the System. The System checks whenever the given clientNumber is valid. The Client gives the name of the DVD he wants to rent. ... n. ...I will later have to form an association between a new instance of "RentDVD" class concept to the current Client c. My Domain Model is something like: I've made the Contract for the first and second operations as: Preconditions: none Postconditions: there exists a Client c such that c.clientNumber = clientNumber. Now, I don't know if I should form an association between this Client c and the DVDStore(that I intend to use as front-end). If I don't make the association, how will I later be able to "reference" this same Client? Should I be making an association between Client and a different concept? Thanks

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