my $sth = $dbh->prepare('INSERT INTO foo SET '
                            . "bar  = isnull(?, 'default_bar'), '
                            . "blah = isnull(?, 'default_blah')) "

##</code><code>##

Bareword found where operator expected at line 442, near ". "blah
"
  (Might be a runaway multi-line "" string starting on line 441) (#1)
    (S syntax) The Perl lexer knows whether to expect a term or an operator.
    If it sees what it knows to be a term when it was expecting to see an
    operator, it gives you this warning.  Usually it indicates that an
    operator or delimiter was omitted, such as a semicolon.

        (Missing operator before blah?)
Unquoted string "blah" may clash with future reserved word at line 442 (#2)


##</code><code>##

. "blah = isnull(?, 'default_blah')) "