Oracle中union all、union 和order by一起使用的解决方法

当union all和order by 如下一起使用时，会报sql未正确结束

select name,age from student order by age

union all

select name,age from person order by age

通用的解决方法有三种：

1、将结果集作为一张临时表然后查询排序

select * from (select name,age from student order by age

union all

select name,age from person order by age) order by age

2、单独对表进行排序后进行并集操作

select * from (select name,age from student order by age)

union all

select * from (select name,age from person order by age)

3、order by + 字段在结果集中的序号

select name,age from student 

union all

select name,age from person 

order by 2