In C# Or OOP, Should 2 Classes Reference Each Other That Are Related?
Mar 4, 2010
I am working on a class library using C#. I have designed 3 main classes to model our data. They are designed such that class A contains a list of class B instances, and class B contains a reference to a class C instance, ie:
[code]....
I feel like the class design works well for modeling the data and our business rules, but it does create a few limitations like the above situation. I liked the separation of the PolicyTerm and Billing for the ability to allow that code to be modified and tested independently. Also, I feel like it keeps each section smaller and simpler.
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Jun 4, 2010
I would like to display students and their grades with a GridView and LinqToSQL like this:
assignment1 assignment2
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I have a many-to-many relationship between students and assignments called "grades". The grade for the assignment is stored in that table in a "gradeNumber" column.
I would also like to specify which assignments should be displayed in the grid. Btw, my LINQ entities are extended to allow me to write/get studentx.Assignments or assignmentx.Students.
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Mar 27, 2010
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Jan 11, 2010
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May 17, 2010
I am following the Nerd Dinner tutorial as I'm learning ASP.NET MVC, and I am currently on Step 3: Building the Model. One part of this section discusses how to integrate validation and business rule logic with the model classes. All this makes perfect sense. However, in the case of this source code, the author only validates one class: Dinner.
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This doesn't "feel" right, but I wanted to check with SO to get opinions of individuals smarter than me on this. I also tested it out, and it seems that the partial keyword on the OnValidate method is causing problems (understandably so). This doesn't seem possible to fix (but I could very well be wrong).
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Aug 11, 2010
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[code]....
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Mar 24, 2010
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Dec 15, 2010
I'm curious as to what people consider better practice, between duplicating model structure in the view model and using a mapping tool to move data between the two, or aggregate the model inside the view model, i.e. have a property on the view model class that is a reference to the actual model. Which is considered a better approach in general?
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Aug 6, 2010
I am trying to call web reference "A" in an application.
The web reference "A" will then call a function in another web reference "B" through HTTPS connection (require certificate).
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Jan 7, 2010
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Oct 4, 2010
I am working on converting a project from C# to VB and am facing this weird issue. 1 page cannot compile and I get the reference error, but the weird thing is that the compiler shows the error as coming from ASP.NET generated code. Visual Studio shows me that error is coming from my ASPX page. I cannot seem to figure out why or where this error is occuring. Also if I take the inherits attribute out I don't get the compilation error. The code in aspx page is below:
[Code]....
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Apr 22, 2010
I am using VS2005, and a newbie at table adapters, DAL & BLL. I have a single dataset (in DAL) and 2 classes (in BLL) named Class1.vb and Class2.vb.
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Here is a sketch of my code structure:
[Code]....
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Jan 12, 2010
I have a Web service which, when updated on one computer with VS2008 works perfectly fine, but on another computer does not. The critical difference is the contents of the auto-generated Reference.cs.
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Aug 25, 2010
I have a url like this:
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if(request.querystring["comp"].tostring() != null)
{
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So I got an error like: object reference not set to an instance of reference.My problem is, I am using the same page. So when I go from some page, I will have "comp". but other times not. So when there is no "comp", how do I handle it in request.querystring?
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Oct 8, 2010
I do not receive this error when I open my website application in vs 2005. When I open in vs 2008, I get this error. What gives?
These lines are underlined in blue:
[Code]....
Businesslogic area is imported into each of 3 pages with this line.
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Sep 30, 2010
in my default.aspx page i have a dropdown List and a textbox with a submit button below that there are 2 listbox... and the dropdown list holds the names of the listbox
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[Code]....
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Jun 9, 2010
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Aug 11, 2010
Having the following model Admin and AdminGroup is joined by AdminAdminGroup which has (AdminId, AdminGroupId) fields. When I add a new Admin row AdminGroups are associated with it automatically however this only works on INSERT.When I'm trying to update or associate more AdminGroup's with particualr Admin row (_repo.Update((DataLayer.Admin)row);) only Admin gets updated and no groups are ever modified.What is the correct way of updated "related" entities? so that AdminGroup also get's updated.
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Nov 21, 2010
I want to have two combo boxes: One for categories and one for subcategories. As a category is selected in one combo box, all the related subcategories are displayed in the other combo box. EF 4.0 should be perfect for this. But the subcategory collections are always empty!
[Code]....
I can see that Lazy loading is set to true. I tried setting it to false and adding Include("Subcategories") but the subcategories collection is always empty.
I even tried using the SQL Server Profiler. Although I couldn't explain the timing, I could in some cases see the queries to return the subcategories. I even executed the query and it returned the expected results.
I'm really getting frustrated by EF. Although I'm fairly new to SQL Server, I could've had what I'm working on done hours ago. Instead, it's like a black box with no way for me to troubleshoot or determine what the heck is going wrong.
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Jan 18, 2011
I have 2 tables:
User(Id PK, TitleId FK, Name, Active)
Title(Id PK, Text)
Title is a lookup table of titles (Mr, Miss,...) and its got a relationship with table User by TitleId.
Now I'm trying to display the data in a web page using .net and Entity Framework. I'm using a ListView control and a query as a source. it all displays fine except for the Title.
Here is my code:
MyEntities _entities = new MyEntities (); User user = new User(_entities); IQueryable u = (from x in _entities.Users where x.Active == true select x); ListView1.DataSource = u; ListView1.DataBind();
and the code in the front end:
<asp:ListView ID="ListView1" runat="server" EnableModelValidation="True" DataKeyNames="Id"><ItemTemplate> <tr> <td> <%# Eval("Id") %> </td> <td> <%# Eval("Title.Text") %> </td> <td> <%# Eval("Name") %> </td> </tr></ItemTemplate><LayoutTemplate> <table ID="itemPlaceholderContainer" runat="server"> <tr runat="server"> <th id="Th2" runat="server"> Id</th> <th id="Th1" runat="server"> Title</th> <th id="Th3" runat="server"> Name</th> <th runat="server"> </tr> <tr runat="server" ID="itemPlaceholder"> </tr> </table></LayoutTemplate>
How do I manage to get the Title Text associated with a User to display on the ListView?
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Jun 10, 2010
What i want to do is have a grid i can add rows and columns and cells. each cell i want to have an image button in. I want to do this in a windows form. Is this posible? I was looking into the gridview/datagridview but that wasn't what i wanted.
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Sep 3, 2010
im looking for ecommerce development video tutorial. I already watched related video tutorials on ASP.net website.
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Jan 3, 2011
I have a table articles where i keep all the records of the articles wriiten by people online. Now i need to retrieve related articles based on the title i guess. I tried doing that using my stored procedures with the LIKE operator, but i guess that doesn't work because it does not take the whole string of the title and match with the ones in the database.
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Nov 9, 2010
Here's my DB structure:
I have three tables.
User, Details, Optional
User has fields: ID, FirstName, LastName
Details has fields: ID, MyDetails1, MyDetails2, User_ID
Optional has fields: ID, MyOptions1, MyOptions2, User_ID
There is a 1 to many relationship with User & Detail (User ID & Detail User_ID)
There is a 1 to many relationship with User & Optional (User ID & Optional User_ID)
With that said, one user can have many details and/or many optionals
Now I'm trying to build a linq query that will say:
"where user id = x, select FirstName, LastName, all MyDetails1 from every record where User_ID == x, all MyOptions1 from every record where User_ID == x"
After the merge I should have one string that lists the distict user & all of their many fields:
FirstName + LastName + (MyDetails1 + MyDetails1 + MyDetails1..etc) + (MyOptions1 + MyOptions1)
Anyone try this before?
I tried this with JOIN but this doesn't do the trick for what I'm looking for.
So if I had 3 MyDetails records associated with ID == 2, I would get three results like:
John Doe MyDetails_X
John Doe MyDetails_Y
John Doe MyDetails_Z
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May 20, 2010
What's the best way in ASP.NET MVC to get a few questions related to the current question (like on stackoverflow) without using tags?
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