multiple conflict targets

Hi,

if I read https://www.postgresql.org/docs/9.6/static/sql-insert.html
correctly there can be only one conflict target or none at all.

What if I have a table with 3 unique constraints? If the first one is
violated by the insert I want to do nothing. If the 2nd is violated some
fields should be updated. And violation of the 3rd one should raise an
error.

Can that be expressed?

Thanks,
Torsten