listagg

listagg (filedname,',') WITHIN GROUP (ORDER BY filedname)

行转列函数。

teledb=# create table person
teledb-# (
teledb(#    deptno varchar2(10),
teledb(#    ename  varchar(20)
teledb(# );
CREATE TABLE
teledb=# insert into person values('20','aaa');
INSERT 0 1
teledb=# 
teledb=# insert into person values('20','bbb');
INSERT 0 1
teledb=# 
teledb=# insert into person values('20','ccc');  
INSERT 0 1
teledb=# 
teledb=# insert into person values('21','ddd');
INSERT 0 1
teledb=# 
teledb=# insert into person values('21','eee');
INSERT 0 1
teledb=# select
teledb-#     deptno,
teledb-#     listagg (ename,',') WITHIN GROUP (ORDER BY ENAME)
teledb-# from
teledb-#     person   
teledb-# group by
teledb-#     deptno ;
 deptno |   listagg   
--------+-------------
 20     | aaa,bbb,ccc
 21     | ddd,eee
(2 rows)