oracle取第二大的值,【Oracle】oracle取最大值和最小值的几个方法汇总

(1)oracle使用keep分析函数取最值记录

-- 取工资sal最大的雇员姓名及其工资，以及工资sal最少的雇员姓名及其工资

select

deptno,

empno,

ename,

sal,

max(ename) keep(dense_rank FIRST order by sal) over (partition by deptno) as min_sal_man,

max(sal) keep(dense_rank FIRST order by sal) over (partition by deptno) as min_sal,

max(ename) keep(dense_rank LAST order by sal) over (partition by deptno) as max_sal_man,

max(sal) keep(dense_rank LAST order by sal) over (partition by deptno) as max_sal

from emp

where deptno=10

结果如下：

从语句中可以看到，ename和sal都是用的max()，这样做的目的是为了去除由于keep()函数得到的有重复值的数据结果集。这样用有一个弊端，加入部门20有两个相同的最大SAL的人，部门30有两个相同的最小SAL的人，如果按照这种方法取出来的数据，就不一定准确了，重复的人会被去除掉。

我们用下面的语句来修改一下：

select

deptno,

empno,

ename,

sal,

max(ename) keep(dense_rank FIRST order by sal) over (partition by deptno) as min_sal_man,

max(sal) keep(dense_rank FIRST order by sal) over (partition by deptno) as min_sal,

max(ename) keep(dense_rank LAST order by sal) over (partition by deptno) as max_sal_man,

max(sal) keep(dense_rank LAST order by sal) over (partition by deptno) as max_sal,

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