这个就直接把答案写在下面，想自己做的小伙伴可以不看下面的答案，自己尝试着先做一下

ID	NAME
1	'张三，李四，王五'
2	'a,b,c,d,e'

    想要拆解成下面这样子：

ID	NAME
1	张三
1	李四
1	王五
2	a
2	b
2	c
2‍	d
2	e

    话不多说，直接上代码，想做题的小伙伴就不用往下看了，直接关注我，想看答案的可以继续~

    刚开始编写文章，很多地方都有不足，希望以后可以为大家贡献出更好的文章，谢谢大家！有哪里不明白的地方可以和作者联系〜

    没有关注的也可以关注下公众号〜再次感谢

                    

-----第一种方法-- 创建需要划分的字符串  with T1 as(      select 1 as id ,'张三,李四,王五' as name from dual    union all    select 2 as id ,'a,b,c,d,e' as name from dual     ),       -- 统计字符串中子串的个数  -- 字符串中','字符用''代替后，其减少的长度自然就是原串中','字符的个数  T2 as(     select id,length(T1.name) - length(replace(T1.name, ',', '')) + 1            as source_substring_count       from T1),       -- 根据子串的个数创建索引列，用于给T4的regexp_substr()方法索引  T3 as(     select id,rownum as row_number        from dual, T2           connect by rownum <= T2.source_substring_count),       -- 根据每个索引值逐个截取字符串  T4 as(     select t1.id, T3.row_number as substring_index,            regexp_substr(T1.name, '[^,]+', 1, T3.row_number) as substring       from T1, T3)       select id, substring_index, substring from T4where substring is not null

-------第二种方法with tt as ( select 1 as id, '张三,李四,王五' || ',' as name    from dual  union all  select 2, 'a,b,c,d,e' || ',' from dual  ),t1(id,name,lev) as (select id, substr(name, 1, instr(name, ',', 1, 1) - 1) as name, 1 as lev    from tt  union all  select t.id,         substr(t.name,                instr(t.name, ',', 1, t1.lev) + 1,                instr(t.name, ',', 1, t1.lev + 1) -                instr(t.name, ',', 1, t1.lev) - 1) as name,         lev + 1 as lev    from t1   inner join tt t      on t1.id = t. id     and instr(t.name, ',', 1, t1.lev + 1) > 0)select id, name, lev from t1

------第三种方法with tt as (select 1 as id, '张三,李四,王五' || ',' as name    from dual  union all  select 2, 'a,b,c,d,e' || ',' from dual),t1(id,name,lev) as (select id, regexp_substr(name, '[^,]+', 1, 1) as name, 1 as lev    from tt  union all  select t.id,         regexp_substr(t.name, '[^,]+', 1, lev + 1) as name,         t1. lev + 1 as lev    from t1   inner join tt t      on t1.id = t. id     and instr(t.name, ',', 1, t1.lev+1) > 0)select id, name, lev from t1

今天就到这里，有什么不明白可以联系我~~~