Listagg
select
*
from emp
select LISTAGG(ename,‘-‘)
within
group
(order
by deptno desc)
from emp;
可以看到功能类似wm_concat，可以自定义连接符，区别：
LISTAGG? : 11g2才提供的函数，不支持distinct,拼接长度不能大于4000,函数返回为varchar2类型，最大长度为4000.
和wm_concat相比，listagg可以执行排序。例如
select deptno, listagg(ename,‘;‘)
within
group(order
by ename) enames from emp group
by deptno;
with table as
?SQL Code?
|
1 2 3 4 5 6 7 8 9 10 11 12 13 |
? |
with?temp?as( ??select?500?population,?‘China‘?nation?,‘Guangzhou‘?city?from?dual?union?all ??select?1500?population,?‘China‘?nation?,‘Shanghai‘?city?from?dual?union?all ??select?500?population,?‘China‘?nation?,‘Beijing‘?city?from?dual?union?all ??select?1000?population,?‘USA‘?nation?,‘New?York‘?city?from?dual?union?all ??select?500?population,?‘USA‘?nation?,‘Bostom‘?city?from?dual?union?all ??select?500?population,?‘Japan‘?nation?,‘Tokyo‘?city?from?dual? ) select?population, ???????nation, ???????city, ???????listagg(city,‘,‘)?within?GROUP?(order?by?city)?over?(partition?by?nation)?rank from?temp |
With table as 类似创建一个临时表，只可以查询一次，之后就被销毁，同时可以创建多个临时table，比如：
with sql1 as
(select to_char(a) s_name from test_tempa),
sql2 as
(select to_char(b) s_name
from test_tempb
where
not
exists
(select s_name from sql1 where
rownum
=
1))
select
*
from sql1
union
all
select
*
from sql2
pivot unpivot
行列转换，见