ORACLE Top/Bottom N、First/Last、NTile
目录
==================================================================
1.带空值的排列
2.Top/Bottom N查询
3.First/Last排名查询
4.按层次查询
一、带空值的排列：
假如被排列的数据中含有空值呢？
SQL> select region_id, customer_id,
2 sum(customer_sales) cust_sales,
3 sum(sum(customer_sales)) over(partition by region_id) ran_total,
4 rank() over(partition by region_id
5 order by sum(customer_sales) desc) rank
6 from user_order
7 group by region_id, customer_id;
REGION_ID CUSTOMER_ID CUST_SALES RAN_TOTAL RANK
---------- ----------- ---------- ---------- ----------
10 31 6238901 1
10 26 1808949 6238901 2
10 27 1322747 6238901 3
10 30 1216858 6238901 4
10 28
相关文档：
1、序列定义
ORACLE:
CREATE SEQUENCE <sequence_name>
INCREMENT BY <integer>
&n ......
CREATE OR REPLACE PROCEDURE sendemailtest
(mailmsg IN Varchar2)
IS
--using mail server to send email.
mailconn UTL_SMTP.connection;
mailhost & ......
由于系统移植，原来的数据库编码和时区都换了，原来的一些SQL文也出错了。。
经常崩出"ORA-01846: not a valid day of the week
"错误。
经测试，以下这个简单语句也会错！！
SQL> select next_day(sysdate,'FRIDAY') from DUAL;
select next_day(sysdate,'FRIDAY') from DUAL
ORA-01 ......
Oracle主键自动增长
这几天搞Oracle，想让表的主键实现自动增长，查网络实现如下：
create table simon_example
(
id number(4) not null primary key,
name varchar2(25)
)
-- 建立序列：
-- Create sequence
create sequence SIMON_SEQUENCE &nb ......
