in reply to Don't print on the last loop

The easiest way is to move the comma printing to the front of the loop, and add a flag to control printing it: 
   my $add_comma=0;
   while ( my ( $cat, $schem, $tn, $cn, $dt, $tyn, $cs, $bl, $dd, $npr
+, $nul) = $sth->fetchrow_array()) { 
      if ($add_comma++) {
          print ",\n";
      }
      print "\t$cn ";
      if (($tyn eq 'DATETIME') || ($tyn eq 'DOUBLE')) {
         print "$tyn";
      } else {
         print "$tyn($cs)";
      }
      print " not null" if ($nul == 0);
   }

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Remember: There's always one more bug.

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Re^2: Don't print on the last loop
by calin (Deacon) on Jun 13, 2005 at 20:20 UTC

    Another idea is to unroll the first iteration of the loop. This way you don't have to test for a flag on subsequent iterations. I believe this is the correct approach optimisation-wise - if one condition is true only once and then guaranteed false for the next 1.000.000 times, checking it programatically (and doing other stuff like modifying the flag variable) 1.000.001 times is a waste. Pseudocode:

    if ( CONDITION ) {
  do_iteration();
  while ( CONDITION ) {
    print ",\n";
    do_iteration();
  }
}

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[d/l]
Re^2: Don't print on the last loop
by omega_monk (Scribe) on Jun 13, 2005 at 14:30 UTC
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