+ my $left_is_not =($left && $left->name() && $left->name() eq "NOT");
+ my $right_is_not=($right && $right->name() && $right->name() eq "NOT");
+ my $join=undef;
+ # if we are ANDing, add an inner join
+ # also if we are NOTing, but we are looking for a tag *value*
+ if($op eq "AND")
+ {
+ # if right child is a NOT, we don't need extra join/brackets
+ # NOT will do the same and we will end up with an extra one
+ $join= "INNER" unless($right_is_not);
+ }
+ elsif($op eq "NOT")
+ {
+ $not=1;
+ # as above - if right child is a NOT, we don't need extra join/brackets
+ # NOT will do the same and we will end up with an extra one
+ $join = ($hasvals ? "INNER" : "LEFT") unless($right_is_not);
+ }
+ elsif($op eq "OR")
+ {
+ # if left child is a NOT, we need an extra (inner) join
+ # unless right child is also a NOT
+ $join="INNER" if($left_is_not && ! $right_is_not)
+ }
+ if($join)
+ {
+ push(@joins, $join);
+ push(@outjoins, $join);
+ }