gistfile1.rb

# vim:set encoding=utf-8:
# by ruby1.9.1-p378

require "dbi"
require "kconv"

DBI.connect("DBI:ODBC:foobar", "sa", "sa") do |dbh|
  q = "select * from foo_table"
  dbh.select_all(q) do |row|
    row[0] = NKF.nkf("-wZ1", row[1]).strip
    row[0] = row[0].gsub(/([ａ-ｚＡ-Ｚ０-９])/){ NKF.nkf("-wWZ", $1) }
    #=> ok
    row[1] = row[1].gsub(/([ａ-ｚＡ-Ｚ０-９])/){ NKF.nkf("-wWZ", $1) }
    row[1] = NKF.nkf("-wZ1", row[1]).strip
    #=> error
    #   `gsub': incompatible encoding regexp match
    #   (UTF-8 regexp with ASCII-8BIT string)
    #   (Encoding::CompatibilityError)
  end
end