- sequence support; has_sequence, create/drop
- FoundationDB seems to do "standard_conforming_strings" so remove backslash escaping
- update statement used to get at identity sequence
- support RETURNING + prefetch sequence; remove get_lastrowid() and switch
to get_insert_default() like the postgresql dialect does.
- FoundationDB does an empty insert as "VALUES (default)", however we don't have a compiler
hook for that right now and they say that "DEFAULT VALUES" is a TODO; so mark
"empty inserts" as unsupported for now, would be better to wait for that to be done.
- using the latest DBAPI which has a fix for multiple cursors with different nesting flags,
all tests pass.
- reflection tests are still skipped, pending completion of full reflection support