oracle登陆账号忘了部分常用sql，适用于oracle

部分常用sql，适用于oracle。上一个月时间：

to_char(add_months(sysdate, -1),'yyyymm')

字符串补零：

to_char(0.68,'FM9999990.0099')

近10天：

select to_char((to_date(to_char(sysdate,'yyyymmdd'),'yyyymmdd') – 10) + rownum,'yyyymmdd') rq from dual a connect bylevel <= 10

同列按顺序合并：

selectid, sys_connect_by_path(name, ',')
from (select id,
name,
row_number() over(partitionby id order by name) rn,
count(*) over(partitionby id) cnt
from test1) a
where level = cnt
start with rn = 1
connect by prior id = id
and prior rn = rn – 1

生成32位随机数：

select sys_guid() from dual

CLOB字段转换成varchoracle账号ar:

dbms_lob.substr(clobcolumn,4000)