Question

我有一个像这样的数据库表：

citizen-gender-age-personid
uk      female-35 -1
uk      male  -35 -1
de      male  -24 -2
gr      female 15 -3
        female 15 -3
ab      male   20 -4 
        male   20 -4
ab      female 21 -5

所以personid可能有多个年龄或性别或公民或所有nullable。我必须编写一个sql，结果必须只是所有personid.like的一条记录：

uk      female-35 -1
de      male  -24 -2
gr      female 15 -3
ab      male   20 -4
ab      female 21 -5

Answer 1

SELECT personid
      ,MAX(age) AS age
      ,MAX(gender) AS gender
      ,MAX(citizen) AS citizen
FROM TableName 
GROUP BY personid;

Answer 2

我找到了解决方案：

  SELECT t.citizen, t.gender, t.age,count(distinct(personid)) FROM table1 t

，其中 rowid =（SELECT MAX（ROWID）从 table1 B 哪里 t.personid = B.personid）group by t.citizen，t.gender，t.age

Oracle按rowid选择不同的组

2 个答案: