How do I Relate these 4 Tables

Posted by Baddie on Stack Overflow See other posts from Stack Overflow or by Baddie
Published on 2009-11-19T22:55:40Z Indexed on 2010/04/06 22:13 UTC
Read the original article Hit count: 339

Filed under:

entity-framework

|

entity-relationship

Trying to setup a simple Thread/Poll table mapping.

Here is what I have:

Threads table

ThreadID (Primary Key/Identity Column)

Polls table

PollID (Primary Key, FK for ThreadID for one-to-one relation)
Question

PollOptions table

PollOptionID (Identity/Primary Key)
Text
PollID

PollVotes table

PollVoteID (Primary Key/Identity)
PollOptionID

I'm not sure if this is a proper relationship. It seems wrong but I'm not sure whats wrong with it.

A Thread can have 0 or 1 Poll.

A Poll can have 2 or more PollOptions.

A PollOption can have 0 or many PollVotes.

I'm going to be using Entity Framework and before I generate the code for it (VS 2010, .NET 4) I want to make sure I have the proper relationship mapping.

© Stack Overflow or respective owner

Related posts about entity-framework

Differences Between NHibernate and Entity Framework

as seen on ASP.net Weblogs - Search for 'ASP.net Weblogs'
Introduction NHibernate and Entity Framework are two of the most popular O/RM frameworks on the .NET world. Although they share some functionality, there are some aspects on which they are quite different. This post will describe this differences and will hopefully help you get started with the one… >>> More
Entity Framework & Binding syncronisation

as seen on Stack Overflow - Search for 'Stack Overflow'
* EDIT * Sorry, I should make it clearer. Imagine I have an entity: public class MyObject { public string Name { get; set; } } And I have a ListBox: <ListBox x:Name="lbParts"> <ListBox.ItemTemplate> <DataTemplate> <TextBlock Text="{Binding Name}"/> … >>> More
Joins and UI Binding with the Entity Framework

as seen on Internet.com - Search for 'Internet.com'
Learn how to build queries with the Entity Framework that involve multiple tables as well as binding in the UI with the EntityDataSource. >>> More
Frederick .NET User Group April 2010 Meeting

as seen on Geeks with Blogs - Search for 'Geeks with Blogs'
FredNUG is pleased to announce that we have an excellent speaker lined up for April. On April 20th, we’ll start with pizza and social networking at 6:30 PM. Then, starting at 7 PM, Dane Morgridge will present “Getting Started with Entity Framework 4” The scheduled agenda is: 6:30 PM - 7:00… >>> More
[News] NHibernate vs MS Entity Framework

as seen on Dot Net Guru - Search for 'Dot Net Guru'
Voil? une question qui se posera de plus en plus avec la sortie prochaine de .NET V4 et Entity Framework V4, l'outil de mapping objet/relationnel de Microsoft. M?me s'il est vrai que l'opinion de Ayende peut para?tre biais?e du fait qu'il est contributeur NHibernate, son point de vue et surtout ses… >>> More

Related posts about entity-relationship

Entity Relationship Diagram - Relationship Strength?

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I am trying to figure out under what circumstances I should use weak (non-identifying) relationships (where the primary key of the related entity does not contain a primary key component of the parent entity), verses when I should use strong (identifying) relationships (primary key of the related… >>> More
Entity Relationship Model: Ternary Relationships

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I am trying to understand why this statement in the book is wrong: "given a C entity, there is at most one related A entity and at most one related B entity". Is it that it doesn't apply to a specific kind of relationship?? So, if I have an example of a student who is in attendance to a course… >>> More
Foreign key onto weak entity set in MS SQL Server 2008?

as seen on Stack Overflow - Search for 'Stack Overflow'
I'm using Microsoft SQL Server 2008 Management Studio to create a relational schema by following an Entity-Relationship diagram. (included below; unrelated details removed) Until now, primary and foreign keys have been working as expected. But when I try to create a foreign key from the entity… >>> More
Entity Relationship diagram - Composition

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I am implementing a small database(university Project) and i am facing the following problem. I created a class diagram where i have a class Train {Id, Name, Details} And a class RollingStock which is than generalized in Locomotive and FreightWagon. A train is Composed by multiple RollingStock… >>> More
Entity Relationship Diagramming

as seen on Stack Overflow - Search for 'Stack Overflow'
I'd like to improve my understanding of cardinality constraints in ER diagrams. I have two entities: User Location But, I want the relationship between these two entities to be many-to-many (a user can be in many locations and a location can have many users). To do this I need to introduce an… >>> More