Beefy Boxes and Bandwidth Generously Provided by pair Networks
more useful options

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??
Greetings monks,

Recently I have been asked to design a perl module (backed by a database) to provide access to a data, which is essentially of a tree structure type. For example, the data looks like:

Parent Node1/ Child Node 1/ Sub Child Node 1/ Leaf1
My database table has the following columns & data:
id | node_name | parent_id 1 | Parent Node1 | 0 2 | Child Node1 | 1 3 | Sub Child Node1 | 2 4 | Leaf1 | 3

id is autogenerated primary key
parent_id is the "id" of the parent row
node_name is the name of the node.

Apart from the regular new(), node_name(), save() and delete() functions, I plan to provide a parent(), which would query the database and return the parent of the given node (as an object.)

The class will be used to list leaf/node(s), for a given node and also display some sort of heirarchial path (or bread crumb) to the given leaf (by appending the parent's node_name() till parent() returns null)

I seek your advice for:
1. is there an optimal way to design a database table to represent an tree structure ?
2. can I provide a better design to access the heirarchial path without incurring a performance penalty ?

In reply to Tree Structure and Db by InfiniteLoop

Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":

  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?

    What's my password?
    Create A New User
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others taking refuge in the Monastery: (7)
    As of 2015-11-27 11:40 GMT
    Find Nodes?
      Voting Booth?

      What would be the most significant thing to happen if a rope (or wire) tied the Earth and the Moon together?

      Results (726 votes), past polls