Migration oracle auto_increment

I have a schema for ~15 tables in MySQL. I need to migrate it to Oracle
though I’ve never used Oracle before. I see that Oracle doesn’t have an
auto_increment built in. One must create a trigger table for each
auto_incrementing id. I’m contemplating translating my MySQL schema
into a Ruby migration script.

Do you know if Ruby migrations will generate enough SQL to implement
these features seemlessly:

  1. auto increment id column
  2. foreign key constraints
  3. partition tables (by range on to_days())
  4. specify data column sizes (e.g. in SQL I can say varchar(10)) but in
    my limited migrations exposure, it looks like the same column would be
    described simply as string.

I’d consider porting to migrations if it bought me a free translation to
Oracle SQL, including the triggers for auto increment, even if I had to
hand tune the result a bit. Otherwise I may wait and use migrations at
a later date.