DBIx::DBStag::Constraint -

A constraint is a recursive structure for representing query constraints;

  AND ---  x=1
    \
     \---- OR   ---  y>2
            \
             \-----  boolfunc(z)

A constraint is either a bool (AND, OR, NOT) with >0 children, or it can be a leaf node representing an atomic constraint

the constraint corresponds to a SQLTemplate option block; eg

  [ name LIKE &name& ]
  [ name => &name& ]
  [ start > &min_start& ]
  [ start => &start& ]
  [ somefunc(&x&) ]
  [ somefunc(&x&, &y&) ]
  [ somefunc(t.col, &x&, &y&) => &z& ]

the constraint consists of an operator (represented by => in the option block). If no => is present, then it is a simple variable binding.

A constraint can consist of multiple variable bindings

http://stag.sourceforge.net

Chris Mungall <cjm@fruitfly.org>

Copyright (c) 2003 Chris Mungall

This module is free software. You may distribute this module under the same terms as perl itself