addCopy :: String -> Connection -> IO (Maybe Int64)
addCopy isbn_ = handleViolations $ update templ isbn_
  where templ = "UPDATE books SET\
                \ owned = owned + 1,\
                \ available = available + 1\
                \ WHERE isbn = ?"
addCopy :: String -> Connection -> IO (Maybe Int64)
addCopy isbn_ = handleViolations $ update templ isbn_
  where templ = "UPDATE books SET\
                \ owned = owned + 1,\
                \ available = available + 1\
                \ WHERE isbn = ?"
addCopy isbn_ = handleViolations $ update templ isbn_
  where templ = "UPDATE books SET\
                \ owned = owned + 1,\
                \ available = available + 1\
                \ WHERE isbn = ?"