I only know how to do what you're asking in 2 steps. I usualy do something similar to: 
  $g{$_} ||= undef for  @cols;
  my @vals = @g{@cols};

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I'd stick with undef since you're using a database. IIRC, undef translates to NULL to indicate the absence of a value, while 0 is a value.

In reply to Re: Hash slice to get DB values - include undefined values? by mortis
in thread Hash slice to get DB values - include undefined values? by George_Sherston

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