Question

I have been struggling and searching for a solution about this for a couple of days but i cannot find any “best practices” or good explanations of how to achive what i want.

Lets say that I have a database consisting of the following tables (just an example);

Customers (Fields: Id, CustomerName, Location)

Products (Fields: Id, ProductName, ProductCode)

Groups (Fields: Id, GroupName)

I then need to link these together to be shown in a Treeview. For example;

Customer1
    |
    |-Group1
    |    |-Product1
    |    |-Product2
    |
    |-Group2
         |-Product2
         |-Product3
         |-Group3
              |
              |-Product1
              |-Product4

As i said, this is just an example. The real solution consists of other types.

Since the products can occur in several places i need to create a “link table”
to display the hierarchial data.

So i created another table looking like this;

Id (int)
ParentId (int)
ObjectType (int)
GroupId (int)
ProductId (int)
CustomerId (int)

The reason for the ObjectType field is to know in what database i need to check for the items name etc. to display in the treeview.

My question now: Is there any other way to design this database?
I am developing in C# using LINQ etc.

Answer 1

from your example, each level of the tree should be a new link table.

you do not show if group 1 is repeated for more than one customer, should the contents of group1 also be repeated.? but i assume group1 contents are the same no matter which customers are associated.

if you can truly link anything to anything, then the objectType is the way to go… but you would have something like:

parentId
ParentObjectType
childId
childObjectType