# Pastebin I1tlJXWM
$ perl6 -Ilib -e 'use Red;
        
model M is table<mmm> { has Str $.a is column; has Bool $.b is column; has Str $.c is column }
my $*RED-DB = database "SQLite";
M.^create-table; my $*RED-DEBUG = True;
say M.^all.map: { .b ?? .a !! .c }
'
SQL : SELECT
   CASE 
      WHEN (b == 0 OR b IS NULL) THEN c
      WHEN (b <> 0 AND b IS NOT NULL) THEN a

   END
    as "data"
FROM
   mmm
()