NAME

Bio::DB::Query::QueryConstraint - a constraint on a variable value in a query

SYNOPSIS

            

              
              
# create a constraint that says "species not like drosophila*"
my $qc = 
  Bio::DB::Query::QueryConstraint->new(-name=>"species",
                       -op=>"like",
                       -value=>"drosophila*",
                       -neg=>1);
# alternate way of writing same thing
my $qc = 
  Bio::DB::Query::QueryConstraint->new("species like drosophila*");
$qc->neg(1);
# use lisp-style operand-first way of specifying composites
# species taxa id is 7227 or 7228
my $qc = 
  Bio::DB::Query::QueryConstraint->new(
      [   "or", 
       "species=7227", 
    "species=7228",
       "species=7229"
      ]
  );
# composite queries can also be built this way:
my $qc = 
  Bio::DB::Query::QueryConstraint->new(-op=>"or", 
                       value=>[$subqc1, $subqc2, $subqc3]);
$qc->is_composite(1);
# we can have nested constraints like this:
my $qc = 
  Bio::DB::Query::QueryConstraint->new(
      [   "or", 
    [   "and", 
            "species=Human", 
              "keywords=foo*"
          ],
    [   "and", 
                "species=Drosophila virilis", 
              "keywords=bar*"
        ]
      ]
  );
            
          

DESCRIPTION

Represents the constraints in a query; either the whole constraints or a part of; see the composite design patern.

the qc is a leaf node (eg Col=Val) or a composite node (eg (AND cons1, cons2, cons3, ....)

composite nodes have name=composite

Should we split this into two classes ala composite design pattern? Cramming both into one works for now.

CONTACT

Chris Mungall, cmungall@fruitfly.org

APPENDIX

The rest of the documentation details each of the object methods. Internal methods are usually preceded with a _

name

            

              
              
Usage:  $qc->name($val);      # setting
    OR   return $qc->name();  # getting
            
          

the name of the variable being constrained

value

            

              
              
Usage:  $qc->value($val);      # setting
    OR   return $qc->value();  # getting
            
          

the value of the variable is allowed to take mediated by the operand

this is an arrayref of sub-constraints if this a composite

operand

            

              
              
Usage:  $qc->operand($val);      # setting
    OR   return $qc->operand();  # getting
            
          

defaults to "="

neg

            

              
              
Usage:  $qc->neg($val);      # setting
     OR   return $qc->neg();  # getting
            
          

boolean

set if the constraint is to be negated

is_composite

            

              
              
Usage:  $qc->is_composite($val);       # setting
     OR   return $qc->is_composite();  # getting
Returns: boolean
            
          

et if the constraint is a composite constraint (in this case the sub constraints go in $qc->values)