我认为这应该起作用，假设对于每个SEQ值，总会有一行带有ROWSEQNUM=1的行，并且ROWSEQNUM的值按顺序增加没有缝隙.

I think this ought to work, assuming that for each SEQ value there is always a row with ROWSEQNUM=1 and the values for ROWSEQNUM increase sequentially with no gaps.

select seq, min(rowseqnum), max(assoc_list)
from (
  select seq, rowseqnum, sys_connect_by_path(assisting_associate,';') assoc_list
    from assoc_table
    start with rowseqnum=1
    connect by seq = prior seq and rowseqnum = prior rowseqnum + 1
  )
group by seq