Hello all,
Perhaps this is not the right place to post something like this however I have been reading this for months and decided to ask.
I faced with an problem at work where I need to model a simple tree structure from a database. For instance.
ID PARENT_ID NAME
1 NULL Manager
2 1 Employee
3 2 Intern
4 NULL President
5 4 Gov
6 5 Mayor
I am just looking at some general advise as to how one may model this. I would like to have the whole object graph created by the Root objects. Meaning if I go after a Parent I should get the entire object graph.
Any insight would be great. I will keep searching in the mean time.
PitDog
Your object model should reflect your business (user's) use cases, not the data structure.
Is there really a case where the user needs to retrieve all the data in these objects all at once for the purpose of editing? Typically that's not a valid user scenario.
Instead, determine the user scenarios (use cases) that need to be implemented and design objects to match those scenarios. I discuss this in Chapter 6.
Hey Rocky,
Thanks for the reply! One particular use case that I am speaking of is how the menu should work.
Imagine that I have a site selling cars. I want to create a menu that will allow for the user to navigate the cars that my site sells. Granted these are going to be read only objects I will still need to get a object graph with the data needed to build a menu below.
Ford
-Vans
-Van 1
-Van 2
-Cars
-suv
VW
-Cars
- Vans
-Suv
PitDog
P.S. I am very excited about the 2.0 version. I have used your 1.5 framework for 4 projects and it has proven well!!
I replaced NameValueListBase with a similar structure that contains list of nodes (not just name & value) that each node can contain links to other nodes in the list. After implementing IHierarchicalDataSource, I can bind my list to a DropDownList (with the text member being "Extended Display" to either do "-Cars" "--Honda" or "Vehicles/Cars/Honda" "Vehicle/Cars" or a TreeView control (because of IHierarchicalDataSource).
skagen00:
I replaced NameValueListBase with a similar structure that contains list of nodes (not just name & value) that each node can contain links to other nodes in the list. After implementing IHierarchicalDataSource, I can bind my list to a DropDownList (with the text member being "Extended Display" to either do "-Cars" "--Honda" or "Vehicles/Cars/Honda" "Vehicle/Cars" or a TreeView control (because of IHierarchicalDataSource).
Do you mind posting some code here? Thanks
There was actually a question much like this discussed on the old forum just prior to the move to this new one. Here it is:
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