PostgreSQL的window函数整理(8)

来源：未知责任编辑：责任编辑发表时间:2015-09-17 09:42　点击:次

-------------+-----------+-------+--------+-------------

6000 | develop | 8 | 6000 | 2006-10-01

6000 | develop | 10 | 5200 | 2007-08-01

6000 | develop | 11 | 5200 | 2007-08-15

6000 | develop | 9 | 4500 | 2008-01-01

6000 | develop | 7 | 4200 | 2008-01-01

3900 | personnel | 2 | 3900 | 2006-12-23

3900 | personnel | 5 | 3500 | 2007-12-10

5500 | sales | 6 | 5500 | 2007-01-02

5500 | sales | 1 | 5000 | 2006-10-01

5500 | sales | 3 | 4800 | 2007-08-01

5500 | sales | 4 | 4800 | 2007-08-08

(11 rows) www.2cto.com

postgres=# select last_value(salary)over(partition by depname order by salary desc),* from empsalary;

last_value | depname | empno | salary | enroll_date

------------+-----------+-------+--------+-------------

6000 | develop | 8 | 6000 | 2006-10-01

5200 | develop | 10 | 5200 | 2007-08-01

5200 | develop | 11 | 5200 | 2007-08-15

4500 | develop | 9 | 4500 | 2008-01-01

4200 | develop | 7 | 4200 | 2008-01-01

3900 | personnel | 2 | 3900 | 2006-12-23

3500 | personnel | 5 | 3500 | 2007-12-10

5500 | sales | 6 | 5500 | 2007-01-02

5000 | sales | 1 | 5000 | 2006-10-01

4800 | sales | 3 | 4800 | 2007-08-01

4800 | sales | 4 | 4800 | 2007-08-08

(11 rows)

postgres=# select nth_value(salary,2)over(partition by depname order by salary desc),* from empsalary;

nth_value | depname | empno | salary | enroll_date

-----------+-----------+-------+--------+-------------

| develop | 8 | 6000 | 2006-10-01