DBIx::DBStag::Constraint − recursive structure for representing query constraints
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 AT fruitfly DOT org>
Copyright (c) 2003 Chris Mungall
This module is free software. You may distribute this module under the same terms as perl itself