Question

I have the following table structure it might not be a correct structure but unfortunatly that’s what I was given.

id |  Name  | Parent  | Status
 1    First     0       Active
 2    Child     1       Active
 3    2Child    2       Inactive

Logic:

1. Load Root by Parent = 0 and Status

2. OnPopulate load child by parent ID and status for every levels after root

   my issue is if the status is “Inactive” and I want to see what options are inactive I can’t because the first 2 options are active. What I need is to be able to view in my treeview all the levels down to the option that is Inactive or Active.

I have tried the following sql statement

select distinct
        m.Id,
        m.Name,
        m.Parent,
        m.[Status]
from mytable m
where m.Parent = 3 and m.[Status] = 'I'
union
select 
        Id,
        Name,
        Parent,
        [Status]
from mytable
where ID in(select distinct
        o.ID
from mytable o
where o.ID = 3 and o.[Status] = 'I') and Parent = 3

I have ran out of ideas in sql and coding to figure this out..hope someone could guide me in the right direction..thanks

Also tried this in code:

    protected void mytree_TreeNodePopulate(object sender, TreeNodeEventArgs e)
    {
        //this is just a class that loads the values from db
        MYList templist = new ListSyFamily();
        templist.LoadAll();//(ddlStatus.SelectedValue, Convert.ToInt32(e.Node.Value));

        foreach (temp temp in templist)
        {
            if (temp.Status == ddlStatus.SelectedValue && temp.Parent == Convert.ToInt32(e.Node.Value))
            {
                TreeNode child = new TreeNode();
                child.Text = temp.Description;
                child.Value = temp.Id.ToString();
                if (child.ChildNodes.Count == 0)
                    child.PopulateOnDemand = true;

                child.ToolTip = "Ver sub-opciones";
                //child.SelectAction = TreeNodeSelectAction.SelectExpand;

                child.CollapseAll();

                e.Node.ChildNodes.Add(child);
            }
        }
    }

Answer 1

Here is how we handle this.

Assume that you have a class called MyRecord to hold each row of data from the DB:

public class MyRecord
{
    public int Id {get; set; }
    public int ParentId {get; set; }

    public string Name { get; set; }
    public string Status { get; set; }

    // The children of this node
    public MyRecordCollection Children = new MyRecordCollection();
}

Then you have a collection type to hold these records indexed by their id:

public class MyRecordCollection : System.Collections.Generic.Dictionary<int, MyRecord>
{

}

Here is the code (retrieval from the DB not shown) to preprocess the records and then add them to the tree:

        MyRecordCollection cAllRecords;
        MyRecordCollection cParentRecords = new MyRecordCollection();

        // This is a method that just loads the records
        cAllRecords = LoadAllRecords();

        // Cycle through each of the records
        foreach (MyRecord oRecord in cAllRecords.Values)
        {
            if (oRecord.Id == 0)
            {
                // If the record is a parent record, add it to the list of parents
                cParentRecords.Add(oRecord.Id, oRecord);
            }
            else
            {
                // Otherwise, add the current record to its parent's list of children
                cAllRecords[oRecord.ParentId].Children.Add(oRecord.Id, oRecord);
            }
        }

        AddNodesToTree(cParentRecords, this.treeView1.Nodes);

And finally, the recursive method for adding the records to the tree:

    /// <summary>
    /// A recursive method to add all of the records to the specified collection of nodes
    /// </summary>
    /// <param name="cRecords"></param>
    /// <param name="cNodes"></param>
    private void AddNodesToTree(MyRecordCollection cRecords, TreeNodeCollection cNodes)
    {
        foreach (MyRecord oRecord in cRecords.Values)
        {
            TreeNode oNode = new TreeNode();
            oNode.Text = oRecord.Name;
            oNode.Tag = oRecord;
            cNodes.Add(oNode);
            // Now add the node's children if any
            if (oRecord.Children.Count != 0)
            {
                AddNodesToTree(oRecord.Children, oNode.Nodes);
            }
        }

    }