Converting flat data structure into hierarchy Object using c# - c#-4.0

Question

I have the following Flat Data Structure.
ParentAttributeId AttributeId List
----------------- ----------- ------
NULL 29 TestcaseCollection
29 30 EnclosureLeakageDielectricStrengthTest
30 31 DeviceID
30 32 ScannerOneLowChannel
30 33 ScannerTwoLowChannel
29 34 EnclosureLeakageLeakageCurrentTest
34 35 DeviceID
34 36 ScannerOneLowChannel
34 37 ScannerTwoLowChannel
29 38 PatientCircuitLeakageTest
38 39 DeviceID
38 40 ScannerOneLowChannel
38 41 ScannerTwoLowChannel
29 42 SIPSOPDielectricStrengthTest
42 44 ScannerOneHighChannel
42 45 ScannerOneLowChannel
42 46 ScannerTwoHighChannel
42 47 ScannerTwoLowChannel
29 48 SIPSOPLeakageCurrentTest
48 49 ScannerOneHighChannel
48 50 ScannerOneLowChannel
48 51 ScannerTwoHighChannel
48 52 ScannerTwoLowChannel
I need to convert above flat data structure into a hierarchy Object structure like below. So my Object looks like the "List" Column above. I am using SQL Stored Proc to get the above data. I am using C#.
Object hierarchy
29
|
30
| 31
| 32
| 33
|
34
| 35
| 36
|37
38
Any help would be greatly appreciated.
Regards
Niju

Answer 1

You could try something like this:
1) Create a node class
class Node
{
public int ParentId { get; private set; }
public int Id { get; private set; }
public string Label { get; private set; }
public Node Parent { get; set; }
public List<Node> Children { get; } = new List<Node>();
public Node(int parentId, int id, string lable)
{
ParentId = parentId;
Id = id;
Label = lable;
}
public void AddChild(Node child)
{
child.Parent = this;
Children.Add(child);
}
public void Trace(int indent = 1)
{
Enumerable.Range(0, indent).ToList().ForEach(i => Console.Write(" - "));
Console.WriteLine(Label);
Children.ForEach(c => c.Trace(indent + 1));
}
}
2) Create node objects from you flat data and add them to a dictionary
var data = new List<DataRow>() {
new DataRow { ParentId = 0, Id = 1, Label = "parent" },
new DataRow { ParentId = 1, Id = 2, Label = "child 1" },
new DataRow { ParentId = 1, Id = 3, Label = "child 2" },
new DataRow { ParentId = 2, Id = 4, Label = "grand child 1" },
new DataRow { ParentId = 2, Id = 5, Label = "grand child 2" }
};
Dictionary<int, Node> nodes = data.ToDictionary(d => d.Id, d => new Node(d.ParentId, d.Id, d.Label));
3) Build the hierarchy by looping through all nodes calling AddChild on the parent
foreach (var node in nodes.Skip(1))
nodes[node.Value.ParentId].AddChild(node.Value);
If you call Trace() on the top node, the output will look like this:
- parent
- - child 1
- - - grand child 1
- - - grand child 2
- - child 2

Answer 2

Have you looked at AutoMapper?
Not sure this is what you need but it's what I use to often convert from one format to an object model.
Another alternative might be to use LINQ to query the data you have and to create the model for you.
I think you can say something like, and this is untested;
select from dataList select new {....
where new would be the new object you are creating.
However, i think maybe the brute force approach of iterating through your list might still be the way.
edit
this might help.