SSHH网络工作室

摘要：PLSQL中提供了两个内置的统计函数VARIANCE和STDDEV，分别对应于方差和标准差， VARIANCE：方差，数列中各项和平均值的差平方后求和，然后除以数列个数减一，得到的即为方差。 STDDEV：标准差，就是上面算出来的方差的开平方根 阅读全文

摘要：select sid, --日期 sdate, --月初 first_value(rValue) over(partition by sid, substr(sdate, 1, 6) order by sdate) as firstdayofmonth, --月末 last_value(rValue) over(p... 阅读全文

摘要：select to_date(period,'yyyymmdd') as ddate, to_number(substr(period,1,4)) as iyear, to_number(substr(period,5,2)) as imonth, to_number(substr(period,7,2)) as iday, period,prod_chn,prod_eng,ds_chn,cat... 阅读全文

摘要：SQL> select deptno,ename,sal 2 from emp 3 order by deptno; DEPTNO ENAME SAL ---------- ---------- ---------- 10 CLARK 2450 KING 5000 MIL... 阅读全文