When working with SQL's, you probably want to keep your program as simple as possible when constructing SQL's. I often use HEREDOC's to construct SQL queries.

Example:

my $sql = <<EOF;
  SELECT a
  FROM b
  WHERE c
  ORDER BY d
EOF
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Where the a, b, c, d can be variables or hardcoded values.

This is certainly more readable than using a bunch of join's.