Sqoop code generation in 'update' export mode incompatible with '--columns' option

When using sqoop export with --update-key and --columns the options are incompatible. For example, given table T1

  +------+
  | T1   |
  +------+
  | id   |
  | name |
  | mail |
  | cell |
  +-------

When using:

$ sqoop export [ .. ] --update-key id --update-mode allowinsert --columns id,name

the code generation utility creates a Java file which fails to compile.

This seems to happen because ConnManager appends all table columns, even those not mentioned on the command-line (see ConnManager.configureDbOutputColumns). As a result, the generated class contains a write method which references class members which do not exist.

I could suggest two possible solutions: 1) either make this case an exception or 2) make the code that appends all remaining table columns optional.

I may be missing something as that code is there for a reason, but I can't see why?