- Fixed the multiple-table "UPDATE..FROM" construct, only usable on

- Fixed the multiple-table "UPDATE..FROM" construct, only usable on
MySQL, to correctly render the SET clause among multiple columns
with the same name across tables.  This also changes the name used for
the bound parameter in the SET clause to "<tablename>_<colname>" for
the non-primary table only; as this parameter is typically specified
using the :class:`.Column` object directly this should not have an
impact on applications.   The fix takes effect for both
:meth:`.Table.update` as well as :meth:`.Query.update` in the ORM.
[ticket:2912]