use Perl

• You'd be better off converting hierarchies to sets (Score:1)

  by jnoble (503)

  Nat,
  
  I've been doing a bunch of hierarchy work recently in SQL, and the hands-down best way to do the type of typical hierarchy queries that I do in SQL is to store (or at least additionally represent) hiearchies as sets.
  
  See, SQL is a set-operation language. So having hierarchies stored as an adjacency list (e.g. employee table has a 'manager' column) -- although sufficient -- forces you out of SQL and into a procedural language for tree-walking.
  
  Imagine you want to get "this person's management chain" or
  • Re:You'd be better off converting hierarchies to s (Score:1)

    by jnoble (503) on 2003.03.31 15:24 (#18557)

    Crap, my post got its < and > mangled, even though I told the submission widgit it was plain text.

    Here's the decoder guide -- not actual SQL.

    My Management Chain: Select where left LESS THAN my_left AND right GREATER THAN my_right

    My Vast Empire Select where left GREATER THAN OR EQUAL TO my_left AND right LESS THAN OR EQUAL TO my_right Joel Noble

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