Question

我希望从连接表中获取最新日期，其中包含2列中的唯一值。我该怎么做呢？我也尝试过排名（但John排名相同）并尝试了rownum = 1，但由于某种原因我仍然得到相同的结果

Name    ID    Email         DeptNo DeptScore   OnDate
John   A46 john@doe.com       100    50         5/11/2011
John   A46 johndoe@aol.com    200    75         7/21/2015
Alice  B33 alice@hotmail.com  100    50         4/15/2014

我想得到以下内容：

Name    ID    Email         DeptNo DeptScore   OnDate
John  A46  johndoe@aol.com    200    75        7/21/2015
Alice B33  alice@hotmail.com  100    50        4/15/2014

我的查询

select distinct e.name, e.id, e.email, d.deptno, d.deptscore, d.ondate
from
  emp e
inner join dept d on
      d.deptno = e.dnum 
  and d.ondate = e.livedate
  and d.ondate = (select max(m.ondate)
                  from dept m
                  where d.ondate = m.ondate)
--where e.id in ('A46','B33')

Answer 1

尝试使用以下查询，它将解决您的问题。

select  name,
        id,
        email,
        deptno,
        deptscore,
        ondate
from  (select   e.name,
                e.id,
                e.email,
                d.deptno, 
                d.deptscore, 
                d.ondate,
                rank() over(partition by e.id,e.name order by d.ondate desc) rn
        from emp e join
             dept d
             on d.deptno = e.dnum and d.ondate = e.livedate
      ) s
where rn = 1;

输出：

NAME    ID  EMAIL                DEPTNO DEPTSCORE   ONDATE
John    A46 johndoe@aol.com      200    75          21-JUL-15
Alice   B33 alice@hotmail.com    100    50          15-APR-14

从包含具有唯一值

1 个答案: