Are there any other ways of refactoring SQL-heavy code like this?

There are at least two other approaches to consider:

• Store the SQL in a text file rather than as Perl code. For example, Class::Phrasebook::SQL uses XML to store the query definitions, or you could quickly whip up a plain-text file format.

• Have the SQL generated for you rather than hard-coding every query you might ever need. For example, DBIx::SQLEngine would let you write the above query as:

  my $username = $sqldbh->fetch_one_value( table=>'USERS', columns=>'USE
  +R_NAME', 
    criteria=> { 'USER_ID' => $userid } );
  [download]