oracle 字符串拼接

Question

oracle 字符串拼接

Answer 1

select t1.b || '-' || t2.b
from (select a, b from A where d = 1) t1,
(select a, replace(wm_concat(c), ',', '-') b
from A
start with d = 1
connect by b = prior c
group by a) t2
where t1.a = t2.a