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  • How to structure a Genetic Algorithm class hierarchy?

    - by MahlerFive
    I'm doing some work with Genetic Algorithms and want to write my own GA classes. Since a GA can have different ways of doing selection, mutation, cross-over, generating an initial population, calculating fitness, and terminating the algorithm, I need a way to plug in different combinations of these. My initial approach was to have an abstract class that had all of these methods defined as pure virtual, and any concrete class would have to implement them. If I want to try out two GAs that are the same but with different cross-over methods for example, I would have to make an abstract class that inherits from GeneticAlgorithm and implements all the methods except the cross-over method, then two concrete classes that inherit from this class and only implement the cross-over method. The downside to this is that every time I want to swap out a method or two to try out something new I have to make one or more new classes. Is there another approach that might apply better to this problem?

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  • should this database table be normalized?

    - by oo
    i have taken over a database that stores fitness information and we were having a debate about a certain table and whether it should stay as one table or get broken up into three tables. Today, there is one table called: workouts that has the following fields id, exercise_id, reps, weight, date, person_id So if i did 2 sets of 3 different exercises on one day, i would have 6 records in that table for that day. for example: id, exercise_id, reps, weight, date, person_id 1, 1, 10, 100, 1/1/2010, 10 2, 1, 10, 100, 1/1/2010, 10 3, 1, 10, 100, 1/1/2010, 10 4, 2, 10, 100, 1/1/2010, 10 5, 2, 10, 100, 1/1/2010, 10 6, 2, 10, 100, 1/1/2010, 10 So the question is, given that there is some redundant data (date, personid, exercise_id) in multiple records, should this be normalized to three tables WorkoutSummary: - id - date - person_id WorkoutExercise: - id - workout_id (foreign key into WorkoutSummary) - exercise_id WorkoutSets: - id - workout_exercise_id (foreign key into WorkoutExercise) - reps - weight I would guess the downside is that the queries would be slower after this refactoring as now we would need to join 3 tables to do the same query that had no joins before. The benefit of the refactoring allows up in the future to add new fields at the workout summary level or the exercise level with out adding in more duplication. any feedback on this debate?

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  • Create inherited class from base class

    - by Raj
    public class Car { private string make; private string model; public Car(string make, string model) { this.make = make; this.model = model; } public virtual void Display() { Console.WriteLine("Make: {0}", make); Console.WriteLine("Model: {0}", model); } public string Make { get{return make;} set{make = value;} } public string Model { get{return model;} set{model = value;} } } public class SuperCar:Car { private Car car; private int horsePower; public SuperCar(Car car) { this.car = car; } public int HorsePower { get{return horsePower;} set{horsepower = value;} } public override void Display() { base.Display(); Console.WriteLine("I am a super car"); } When I do something like Car myCar = new Car("Porsche", "911"); SuperCar mySupcar = new SuperCar(myCar); mySupcar.Display(); I only get "I am a supercar" but not the properties of my base class. Should I explicitly assign the properties of my base class in the SuperCar constructor? In fact I'm trying Decorator pattern where I want a class to add behaviour to a base class.

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  • SQL database problems with addressbook table design

    - by Sebastian Hoitz
    Hello! I am writing a addressbook module for my software right now. I have the database set up so far that it supports a very flexible address-book configuration. I can create n-entries for every type I want. Type means here data like 'email', 'address', 'telephone' etc. I have a table named 'contact_profiles'. This only has two columns: id Primary key date_created DATETIME And then there is a table called contact_attributes. This one is a little more complex: id PK #profile (Foreign key to contact_profiles.id) type VARCHAR describing the type of the entry (name, email, phone, fax, website, ...) I should probably change this to a SET later. value Text (containing the value for the attribute). I can now link to these profiles, for example from my user's table. But from here I run into problems. At the moment I would have to create a JOIN for each value that I want to retrieve. Is there a possibility to somehow create a View, that gives me a result with the type's as columns? So right now I would get something like #profile type value 1 email [email protected] 1 name Sebastian Hoitz 1 website domain.tld But it would be nice to get a result like this: #profile email name website 1 [email protected] Sebastian Hoitz domain.tld The reason I do not want to create the table layout like this initially is, that there might always be things to add and I want to be able to have multiple attributes of the same type. So do you know if there is any possibility to convert this dynamically? If you need a better description please let me know. Thank you!

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  • Should we seal Singletons? Should we try to inherit from Singletons in the first place?

    - by devoured elysium
    Should a Singleton class be allowed to have children? Should we seal it? What are the pro's and con's? For being able to inherit from a Singleton class, we would have to make the constructor protected instead of private. Now, that will be fine in c#, but the protected word in java gives both child-classes and package-classes access to the constructor. Which means not only classes that inherit from our Singleton can access the constructor but other classes in the same package can do it. I'm a bit confused about all this facts. Maybe I am making a big fuss about nothing to worry about too much? Until now, I never had any necessity of trying to inherit from a Singleton, so maybe this is just an academic question! Thanks

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  • Address calling class [Java]

    - by Samuel
    Hello! [I am rather new to Java and Object Oriented programming] I have an abstract class Moveable with the method abstract void move() which is extended by the class Bullet and the abstract class Character, and Character is extended by the class Survivor and the class Zombie. In Survivor and Bullet the move() method doesnt require any parameters while in the class Zombie the move() method depends on the actual position of the survivor. The survivor and multiple zombies are created in the class Gui. I wanted to access the survivor in Zombie - what's the best way of doing this? In Gui i wrote a method getSurvivor() but i don't see how to access this method in Zombie? I am aware that as a workaround i could just pass a [Survivor survivor] as parameter in move() and ignore it in Bullet and Survivor, but that feels so ... bad practice. Thank you for your time! Samuel [I am not sure what tags to set here, please correct me if i'm wrong]

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  • Stackoverflow login system using fb-connect

    - by Arkid
    I have created my stackoverflow account using my Google Open ID. However, Once I login to stackoverflow, I am never logged out even if I log out from Gmail in a different tab. Can the same be done using an FB login. I mean even if i login using FB and log out from FB, it doesnot log me out from the authenticated and authorized website?

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  • Implementing IDisposable on a subclass when the parent also implements IDisposable

    - by Tanzelax
    I have a parent and child class that both need to implement IDisposable. Where should virtual (and base.Dispose()?) calls come into play? When I just override the Dispose(bool disposing) call, it feels really strange stating that I implement IDisposable without having an explicit Dispose() function (just utilizing the inherited one), but having everything else. What I had been doing (trivialized quite a bit): internal class FooBase : IDisposable { Socket baseSocket; private void SendNormalShutdown() { } public void Dispose() { Dispose(true); GC.SuppressFinalize(this); } private bool _disposed = false; protected virtual void Dispose(bool disposing) { if (!_disposed) { if (disposing) { SendNormalShutdown(); } baseSocket.Close(); } } ~FooBase() { Dispose(false); } } internal class Foo : FooBase, IDisposable { Socket extraSocket; private bool _disposed = false; protected override void Dispose(bool disposing) { if (!_disposed) { extraSocket.Close(); } base.Dispose(disposing); } ~Foo() { Dispose(false); } }

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  • Perl: Exporting variables in a subclass

    - by Jonathan
    I have a base class like this: package MyClass; use vars qw/$ME list of vars/; use Exporter; @ISA = qw/Exporter/; @EXPORT_OK = qw/ many variables & functions/; %EXPORT_TAGS = (all => \@EXPORT_OK ); sub my_method { } sub other_methods etc { } --- more code--- I want to subclass MyClass, but only for one method. package MySubclass; use MyClass; use vars qw/@ISA/; @ISA = 'MyClass'; sub my_method { --- new method } And I want to call this MySubclass like I would the original MyClass, and still have access to all of the variables and functions from exporter. However I am having problems getting the Exporter variables from the original class, MyClass, to export correctly. Do I need to run exporter again inside the subclass? That seems redundant and unclear. Example file: #!/usr/bin/perl use MySubclass /$ME/; -- rest of code But I get compile errors when I try to import the $ME variable. Any suggestions?

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  • Vector of pointers to base class, odd behaviour calling virtual functions

    - by Ink-Jet
    I have the following code #include <iostream> #include <vector> class Entity { public: virtual void func() = 0; }; class Monster : public Entity { public: void func(); }; void Monster::func() { std::cout << "I AM A MONSTER" << std::endl; } class Buddha : public Entity { public: void func(); }; void Buddha::func() { std::cout << "OHMM" << std::endl; } int main() { const int num = 5; // How many of each to make std::vector<Entity*> t; for(int i = 0; i < num; i++) { Monster m; Entity * e; e = &m; t.push_back(e); } for(int i = 0; i < num; i++) { Buddha b; Entity * e; e = &b; t.push_back(e); } for(int i = 0; i < t.size(); i++) { t[i]->func(); } return 0; } However, when I run it, instead of each class printing out its own message, they all print the "Buddha" message. I want each object to print its own message: Monsters print the monster message, Buddhas print the Buddha message. What have I done wrong?

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  • Accessing super class function using subclass object

    - by bdhar
    I have an object for a subclass who is of it's superclass type. There is a overridden function in subclass which gets executed when called using the object. How to call the parent's function using the same object? Is there any way to achieve this? package supercall; public class Main { public static void main(String[] args) { SomeClass obj = new SubClass(); obj.go(); } } class SomeClass { SomeClass() { } public void go() { System.out.println("Someclass go"); } } class SubClass extends SomeClass { SubClass() { } @Override public void go() { System.out.println("Subclass go"); } } Consider the code above. Here it prints Subclass go . Instead I have to print Superclass go .

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  • Inherited variables are not reading correctly when using bitwise comparisons

    - by Shawn B
    Hey, I have a few classes set up for a game, with XMapObject as the base, and XEntity, XEnviron, and XItem inheriting it. MapObjects have a number of flags, one of them being MAPOBJECT_SOLID. My problem is that XEntity is the only class that correctly detects MAPOBJECT_SOLID. Both Items are Environs are always considered solid by the game, regardless of the flag's state. What is important is that Environs and Item should almost never be solid. Here are the relevent code samples: XMapObject: class XMapObject : public XObject { public: Uint8 MapObjectType,Location[2],MapObjectFlags; XMapObject *NextMapObject,*PrevMapObject; XMapObject(); void CreateMapObject(Uint8 MapObjectType); void SpawnMapObject(Uint8 MapObjectLocation[2]); void RemoveMapObject(); void DeleteMapObject(); void MapObjectSetLocation(Uint8 Y,Uint8 X); void MapObjectMapLink(); void MapObjectMapUnlink(); }; XEntity: class XEntity : public XMapObject { public: Uint8 Health,EntityFlags; float Speed,Time; XEntity *NextEntity,*PrevEntity; XItem *IventoryList; XEntity(); void CreateEntity(Uint8 EntityType,Uint8 EntityLocation[2]); void DeleteEntity(); void EntityLink(); void EntityUnlink(); Uint8 MoveEntity(Uint8 YOffset,Uint8 XOffset); }; XEnviron: class XEnviron : public XMapObject { public: Uint8 Effect,TimeOut; void CreateEnviron(Uint8 Type,Uint8 Y,Uint8 X,Uint8 TimeOut); }; XItem: class XItem : public XMapObject { public: void CreateItem(Uint8 Type,Uint8 Y,Uint8 X); }; And lastly, the entity move code. Only entities are capable of moving themselves. Uint8 XEntity::MoveEntity(Uint8 YOffset,Uint8 XOffset) { Uint8 NewY = Location[0] + YOffset, NewX = Location[1] + XOffset; if((NewY >= 0 && NewY < MAPY) && (NewX >= 0 && NewX < MAPX)) { XTile *Tile = GetTile(NewY,NewX); if(Tile->MapList != NULL) { XMapObject *MapObject = Tile->MapList; while(MapObject != NULL) { if(MapObject->MapObjectFlags & MAPOBJECT_SOLID) { printf("solid\n"); return 0; } MapObject = MapObject->NextMapObject; } } if(Tile->Flags & TILE_SOLID && EntityFlags & ENTITY_CLIPPING) { return 0; } this->MapObjectSetLocation(NewY,NewX); return 1; } return 0; } What is wierd, is that the bitwise operator always returns true when the MapObject is an Environ or an Item, but it works correctly for Entities. For debug I am using the printf "Solid", and also a printf containing the value of the flag for both Environs and Items. Any help is greatly appreciated, as this is a major bug for the small game I am working on.

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  • Object hierarchy returned by WCF Service is different than expected

    - by robalot
    Good Day Everyone... My understanding may be wrong, but I thought once you applied the correct attributes the DataContractSerializer would render fully-qualified instances back to the caller. The code runs and the objects return. But oddly enough, once I look at the returned objects I noticed the namespacing disappeared and the object-hierarchy being exposed through the (web applications) service reference seems to become "flat" (somehow). Now, I expect this from a web-service…but not through WFC. Of course, my understanding of what WFC can do may be wrong. ...please keep in mind I'm still experimenting with all this. So my questions are… Q: Can I do something within the WFC Service to force the namespacing to render through the (service reference) data client proxy? Q: Or perhaps, am I (merely) consuming the service incorrectly? Q: Is this even possible? The service code looks like… [ServiceBehavior(InstanceContextMode = InstanceContextMode.PerSession)] public class DataService : IFishData { public C1FE GetC1FE(Int32 key) { //… more stuff here … } public Project GetProject(Int32 key) { //… more stuff here … } } [ServiceContract] [ServiceKnownType(typeof(wcfFISH.StateManagement.C1FE.New))] [ServiceKnownType(typeof(wcfFISH.StateManagement.Project.New))] public interface IFishData { [OperationContract] C1FE GetC1FE(Int32 key); [OperationContract] Project GetProject(Int32 key); } [DataContract] [KnownType(typeof(wcfFISH.StateManagement.ObjectState))] public class Project { [DataMember] public wcfFISH.StateManagement.ObjectState ObjectState { get; set; } //… more stuff here … } [DataContract] KnownType(typeof(wcfFISH.StateManagement.ObjectState))] public class C1FE { [DataMember] public wcfFISH.StateManagement.ObjectState ObjectState { get; set; } //… more stuff here … } [DataContract(Namespace = "wcfFISH.StateManagement")] [KnownType(typeof(wcfFISH.StateManagement.C1FE.New))] [KnownType(typeof(wcfFISH.StateManagement.Project.New))] public abstract class ObjectState { //… more stuff here … } [DataContract(Namespace = "wcfFISH.StateManagement.C1FE", Name="New")] [KnownType(typeof(wcfFISH.StateManagement.ObjectState))] public class New : ObjectState { //… more stuff here … } [DataContract(Namespace = "wcfFISH.StateManagement.Project", Name = "New")] [KnownType(typeof(wcfFISH.StateManagement.ObjectState))] public class New : ObjectState { //… more stuff here … } The web application code looks like… public partial class Fish_Invite : BaseForm { protected void btnTest_Click(object sender, EventArgs e) { Project project = new Project(); project.Get(base.ProjectKey, base.AsOf); mappers.Project mapProject = new mappers.Project(); srFish.Project fishProject = new srFish.Project(); srFish.FishDataClient fishService = new srFish.FishDataClient(); mapProject.MapTo(project, fishProject); fishProject = fishService.AddProject(fishProject, IUser.UserName); project = null; } } In case I’m not being clear… The issue arises as there is a difference in (the name spacing) that I expect to see (returned) is different from what is actually returned. fishProject.ObjectState should look like... srFish.StateManagement.Project.New fishC1FE.ObjectState should look like... srFish.StateManagement.C1FE.New fishProject.ObjectState looks like... srFish.New1 fishC1FE.ObjectState looks like... srFish.New …“Help me Obi-Wan Kenobi, you’re my only hope!”

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  • Pulling data and printing it in an HTML table

    - by John
    Hello, From a MySQL table called "submission" containing the fields "loginid, submissionid, title, url, datesubmitted, displayurl", I would like to print an HTML table thats contains all "title" and corresponding "datesubmitted" where "loginid" equals "$profile." The code I am trying to use is below. It isn't working. Any ideas why it isn't working? Thanks in advance, John $profile = $_GET['profile']; $sqlStr = "SELECT loginid, submissionid, title, url, datesubmitted, displayurl FROM submission WHERE loginid = $profile ORDER BY datesubmitted DESC"; $result = mysql_query($sqlStr); $arr = array(); echo "<table class=\"samplesrec\">"; while ($row = mysql_fetch_array($result)) { echo '<tr>'; echo '<td class="sitename1"><a href="http://www.'.$row["url"].'">'.$row["title"].'</a></td>'; echo '</tr>'; echo '<tr>'; echo '<td class="sitename2">'.$row["datesubmitted"].'</a></td>'; echo '</tr>'; } echo "</table>";

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  • I'm getting an error in my Java code but I can't see whats wrong with it. Help?

    - by Fraz
    The error i'm getting is in the fillPayroll() method in the while loop where it says payroll.add(employee). The error says I can't invoke add() on an array type Person but the Employee class inherits from Person so I thought this would be possible. Can anyone clarify this for me? import java.io.*; import java.util.*; public class Payroll { private int monthlyPay, tax; private Person [] payroll = new Person [1]; //Method adds person to payroll array public void add(Person person) { if(payroll[0] == null) //If array is empty, fill first element with person { payroll[payroll.length-1] = person; } else //Creates copy of payroll with new person added { Person [] newPayroll = new Person [payroll.length+1]; for(int i = 0;i<payroll.length;i++) { newPayroll[i] = payroll[i]; } newPayroll[newPayroll.length] = person; payroll = newPayroll; } } public void fillPayroll() { try { FileReader fromEmployee = new FileReader ("EmployeeData.txt"); Scanner data = new Scanner(fromEmployee); Employee employee = new Employee(); while (data.hasNextLine()) { employee.readData(data.nextLine()); payroll.add(employee); } } catch (FileNotFoundException e) { System.out.println("Error: File Not Found"); } } }

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  • CSS Tables & min-width container?

    - by neezer
    <div id="wrapper"> <div id="header">...</div> <div id="main"> <div id="content">...</div> <div id="sidebar">...</div> </div> </div> #wrapper { min-width: 900px; } #main { display: table-row; } #content { display: table-cell; } #sidebar { display: table-cell; width: 250px; } The problem is that the sidebar isn't always at the right-most part of the page (depending on the width of #content). As #content's width is variable (depending on the width of the window), how to I make it so that the sidebar is always at the right-most part of its parent? Ex. Here's what I have now: <--- variable window width ----> --------------------------------- | (header) | --------------------------------- [content] | [sidebar] | | | | | | | | | | | | | And here's what I want: <--- variable window width ----> --------------------------------- | (header) | --------------------------------- [content] | [sidebar] | | | | | | | | | | | | | Please let me know if you need anymore information to help me with this issue. Thanks! PS - I know I can accomplish this easily with floats. I'm looking for a solution that uses CSS tables.

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  • How to determine which inheriting class is using an abstract class' methods.

    - by Kin
    In my console application have an abstract Factory class "Listener" which contains code for listening and accepting connections, and spawning client classes. This class is inherited by two more classes (WorldListener, and MasterListener) that contain more protocol specific overrides and functions. I also have a helper class (ConsoleWrapper) which encapsulates and extends System.Console, containing methods for writing to console info on what is happening to instances of the WorldListener and MasterListener. I need a way to determine in the abstract ListenerClass which Inheriting class is calling its methods. Any help with this problem would be greatly appreciated! I am stumped :X Simplified example of what I am trying to do. abstract class Listener { public void DoSomething() { if(inheriting class == WorldListener) ConsoleWrapper.WorldWrite("Did something!"); if(inheriting class == MasterListener) ConsoleWrapper.MasterWrite("Did something!"); } } public static ConsoleWrapper { public void WorldWrite(string input) { System.Console.WriteLine("[World] {0}", input); } } public class WorldListener : Listener { public void DoSomethingSpecific() { ConsoleWrapper.WorldWrite("I did something specific!"); } } public void Main() { new WorldListener(); new MasterListener(); } Expected output [World] Did something! [World] I did something specific! [Master] Did something! [World] I did something specific!

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  • ASP: Extend control (ASCX) and access base markup file from subclass code

    - by Pathoschild
    Hello, I'm building form validation controls for our C# ASP application. The bulk of the work is handled by a BaseValidator control (subclassing System.Web.UI.UserControl), which also has the markup for the validation output. This is then extended by subcontrols like PasswordValidator, that provides the Validate method and any extra fields needed by that validator control. (The end goal is to have controls like <uc1:PasswordValidator ControlId="txtPassword" /> which we can plop into any form with minimum duplication.) However, PasswordValidator.ascx.cs cannot access the form elements defined in BaseValidator.ascx; the only way I've found to do so is to duplicate the markup in each subcontrol's *.ascx file. How can I extend BaseValidator.ascx.cs and access BaseValidator.ascx's markup in the subclass?

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  • How can I share variables between a base class and subclass in Perl?

    - by Jonathan
    I have a base class like this: package MyClass; use vars qw/$ME list of vars/; use Exporter; @ISA = qw/Exporter/; @EXPORT_OK = qw/ many variables & functions/; %EXPORT_TAGS = (all => \@EXPORT_OK ); sub my_method { } sub other_methods etc { } --- more code--- I want to subclass MyClass, but only for one method. package MySubclass; use MyClass; use vars qw/@ISA/; @ISA = 'MyClass'; sub my_method { --- new method } And I want to call this MySubclass like I would the original MyClass, and still have access to all of the variables and functions from Exporter. However I am having problems getting the Exporter variables from the original class, MyClass, to export correctly. Do I need to run Exporter again inside the subclass? That seems redundant and unclear. Example file: #!/usr/bin/perl use MySubclass /$ME/; -- rest of code But I get compile errors when I try to import the $ME variable. Any suggestions?

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  • Class Self-Reference

    - by Free Bullets
    I have the following code. The angle function needs some information from the class it was called from. What's the best way to do this? class MyScannedRobotEvent extends robocode.ScannedRobotEvent { public int angle(robocode.Robot myRobot) { return (int) Math.toRadians((myRobot.getHeading() + getBearing()) % 360); } } public class MyRobot extends robocode.Robot { int a = angle(**WHATDOIPUTHERE?**) }

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  • ASP.NET UserControl Inheritence

    - by Craig
    I have a UserControl that is working fine. It is declared like this. public partial class DynamicList : System.Web.UI.UserControl { protected static BaseListController m_GenericListController = null; public DynamicList() { m_GenericListController = new GenericListController(this); } } Now I want to override this control so I can change some of the properties. I have created a class like this. public partial class JobRunningList : DynamicList { public JobRunningList() { m_GenericListController = new JobListController(this); (m_GenericListController as GenericListController).ModuleId = 14; } } It appears that the controls in the DynamicList are not getting created though when I use the JobRunningList control now causing predictably bad results. The DynamicList UserControl has a ListView on it and a few other controls. It appears these are not created when using the JobRunningList. Is there any secret to this?

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  • Inheriting from class that inherits from DynamicObject

    - by SeveQ
    Hello there, I'm experimenting with C# 4.0's dynamic object model. I've created an abstract class named "Block" that inherits from DynamicObject. It overrides TryGetMember and TrySetMember. Furthermore I've created a usable class named "Brush" that inherits from "Block". I want it to be usable dynamically. But when I create a dynamic object from it and try to access a runtime bound member, it pelts me with an exception telling me that the member doesn't exist. The overridden TryGetMember or TrySetMember methods of the abstract parent class aren't getting called. Is this behaviour to be expected? Thank you!

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  • sti and polymorphic's

    - by Alexey Poimtsev
    Hi, I have problem with my code class Post < ActiveRecord::Base end class NewsArticle < Post has_many :comments, :as => :commentable, :dependent => :destroy, :order => 'created_at' end class Comment < ActiveRecord::Base belongs_to :commentable, :polymorphic => true, :counter_cache => true end And on attempt go get comments for some NewsArticle i see in logs something like Comment Load (0.9ms) SELECT "comments".* FROM "comments" WHERE ("comments"."commentable_id" = 1 and "comments"."commentable_type" = 'Post') ORDER BY created_at Strange that "commentable_type" = 'Post'. Whats wrong? PS: Rails 2.3.5 && ruby 1.8.7 (2010-01-10 patchlevel 249) [i686-darwin10]

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  • Best way to enforce inter-table constraints inside database

    - by FerranB
    I looking for the best way to check for inter-table constraints an step forward of foreing keys. For instance, to check if a date child record value is between a range date on two parent rows columns. For instance: Parent table ID DATE_MIN DATE_MAX ----- ---------- ---------- 1 01/01/2009 01/03/2009 ... Child table PARENT_ID DATE ---------- ---------- 1 01/02/2009 1 01/12/2009 <--- HAVE TO FAIL! ... I see two approaches: Create materialized views on-commit as shown in this article (or other equivalent on other RDBMS). Use stored-procedures and triggers. Any other approach? Which is the best option? UPDATE: The motivation of this question is not about "putting the constraints on database or on application". I think this is a tired question and anyone does the way she loves. And, I'm sorry for detractors, I'm developing with constraints on database. From here, the question is "which is the best option to manage inter-table constraints on database?". I'm added "inside database" on the question title. UPDATE 2: Some one added the "oracle" tag. Of course materialized views are oracle-tools but I'm interested on any option regardless it's on oracle or others RDBMSs.

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  • Mapping self-table one-to-many using non-PK clolumns

    - by Harel Moshe
    Hey, i have a legacy DB to which a Person object is mapped, having a collection of family-members, like this: class Person { ... string Id; /* 9-digits string */ IList<Person> Family; ... } The PERSON table seems like: Id: CHAR(9), PK FamilyId: INT, NOT NULL and several other non-relevant columns. I'm trying to map the Family collection to the PERSON table using the FamilyId column, which is not the PK as mentioned above. So, i actually have a one-to-many which is self-table-referential. I'm getting an error saying 'Cast is not valid' when my mapping looks like this: ... <set name="Family" table="Person" lazy="false"> <key column="FamilyId" /> <one-to-many class="Person" /> </set> ... because obviously, the join NHibernate is trying to make is between the PK column, Id, and the 'secondary' column, FamilyId, instead of joining the FamilyId column to itself. Any ideas please?

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