postgres=# select * from test.test_str;
no | name 
----+------------
1 | a,b,c,d
2 | Jason Xian
(2 rows)
将列信息转换成行
postgres=# select regexp_split_to_table(name,',') from test.test_str where no=1;
regexp_split_to_table 
-----------------------
a
b
c
d
(4 rows)
postgres=# select regexp_split_to_table(name,' ') from test.test_str where no=2;
regexp_split_to_table 
-----------------------
Jason
Xian
(2 rows)
postgres=# select regexp_split_to_table('hello world', '\s+');
regexp_split_to_table 
-----------------------
hello
world
(2 rows)

https://blog.csdn.net/MyySophia/article/details/93190190

看这篇文章，行列转换