# Pastebin Cz0Aeet5
$ perl6 -Ilib -e '

use Red;

model M is table<mmm> { has Str $.a is column; has Bool $.b is column }
my $*RED-DB = database "SQLite";
M.^create-table;
M.^all.map: { next if .b; .a }
'
{(mmm.b => False) => mmm.a, (mmm.b => True) => next}