注：先学习sql server里的递归CTE。
假设有兴趣表Hobbys
| Name | Hobby |
| 小张 | 篮球，足球，羽毛球 |
| Name | Hobby |
| 小张 | 篮球 |
| 小张 | 足球 |
| 小张 | 羽毛球 |
采用【递归cte】
with tempHobbys as (select Name,Hobby,charindex(',',Hobby)-1 endindex,0 startindex from Hobbys
union all
select Name,Hobby,charindex(',',Hobby,endindex+2)-1 endindex,endindex+2 startindex from tempHobbys where endindex>-1),
with tempHobbys 2 as (select Name,Hobby,(case when endindex<0 then len(Hobby) else Hobby end) endindex,startindex from tempHobbys)
select Name,substring(Hobby,startindex,endindex-startindex+1) Hobby from tempHobbys2