SQL(Mariadb)将逗号分隔的字符串拆分为行

Question

我有这个专栏:

names
John, Mary
Joseph
Eleanor, Sophia, Dani

我想要这个输出:

names
John
Mary
Joseph
Eleanor
Sophia
Dani

它应该包括 SUBSTRING_INDEX 函数

Answer 1

您可以使用递归 CTE:

with recursive cte as (
      select '            ' as name, concat(names, ',') as names, 1 as lev
      from t
      union all
      select substring_index(names, ',', 1),
             substr(names, instr(names, ',') + 2), lev + 1
      from cte
      where names like '%,%'
     )
select name
from cte
where lev > 1;

Here是一个数据库<> fiddle 。