导读:1建站知识本篇文章是对oracle求同比,环比函数(LAG与LEAD)进行了详细的分析介绍，需要的朋友参考下网站建设网站建设多少钱。

Lag和Lead函数可以在一次查询中取出同一字段的前N行的数据和后N行的值。这种操作可以使用对相同表的表连接来实建设网站公司现，不过使用LAG和LEAD有更高的效率。

复制代码 代码如下:

CREATE TABLE salaryByMonth( employeeNo varchar2(20), yearMonth varchar2(6), salary number) ;insert into SALARYBYMONTH (EMPLOYEENO, YEARMONTH, SALARY)values (1, '200805', 500);insert into SALARYBYMONTH (EMPLOYEENO, YEARMONTH, SALARY)values (1, '200802', 150);insert into SALARYBYMONTH (EMPLOYEENO, YEARMONTH, SALARY)values (1, '200803', 200);insert into SALARYBYMONTH (EMPLOYEENO, YEARMONTH, SALARY)values (1, '200804', 300);insert into SALARYBYMONTH (EMPLOYEENO, YEARMONTH, SALARY)values (1,个业网站建设公司 '200708', 100);commit;

SELECT EMPLOYEENO ,YEARMONTH ,SALARY ,MIN(SALARY) KEEP(DENSE_RANK FIRST ORDER BY YEARMONTH) OVER(PARTITION BY EMPLOYEENO) FIRST_SALARY -- 基比分析 salary/first_salary ,LAG(SALARY, 1, 0) OVER(PARTITION BY EMPLOYEENO ORDER BY YEARMONTH) AS PREV_SAL -- 环比分析，与上个月份进行比较 ,LAG(SALARY, 12, 0) OVER(PARTITION BY EMPLOYEENO ORDER BY YEARMONTH) AS PREV_12_SAL建设网站 -- 同比分析，与上个年度相同月份进行比较 ,SUM(SALARY) OVER(PARTITION BY EMPLOYEENO, SUBSTR(YEARMONTH, 1, 4) ORDER BY YEARMONTH RANGE UNBOUNDED PRECEDING) LJ --累计值 FROM SALARYBYMONTH ORDER BY EMPLOYEENO ,YEARMONTH

关键词标签: 函数 详解 oracle求同比