Question

Let’s say I have a table such as:

D_ID    C_ID    B_ID    A_ID
1D      1C      1B      1A
4D      2C      6B      1A
6D      1C      1B      1A
9D      1C      1B      1A
8D      2C      6B      1A

And let’s say that structurally speaking, I know the following:

A's
 B's
  C's
   D's

That is D’s are children of C’s, C’s of B’s and so on.

How could I turn the table up top into a hierarchical data source?
Such as

ID ParentID
1D  1C
4D  2C
6D  1C
9D  1C
8D  2C
1C  1B
2C  6B
1B  1A
6B  1A
1A  Null

This could then serve as a hierarchical datasource for a Telerik TreeView or other hierarchical controls?
I know I could iterate over every item and build it myself, but I am wondering if there are better known ways to iterate this. Perhaps even a built in way to achieve this.

Answer 1

You could write a simple iteration passing through the file and adding pairs of elements to a dictionary. In pythonish looking psuedo code:

// open the file you want to parse.
file = open(my_log_file)

// create a hash map from ID to parent.
dictionary = {}

// read through the file line by line
for line in file.getlines():
   // ignore first line ...
   // read the 4 columns in each line
   columns[] = line.split(" ")

   // add pairs (id=column[i], parent=column[i+1]) to the hashmap
   dictionary[column[1]] = column[2]
   dictionary[column[2]] = column[3]
   dictionary[column[3]] = column[4]
   dictionary[column[4]] = Nil


// output the hashmap line by line.
print "ID", "Parent ID"
for (id, parent) in dictionary:
  print id, parent

I hope this helps.