Question

我的查询有问题......

这个有效：

  select name, bday, address, dbms_random.value(1, 100) as joker
    from employee 
order by joker asc

但是当我尝试使用'where'和group / having子句获得我想要的东西时，我得到一个ora-00904（无效的标识符）ERROR ..

e.g。

  select name, bday, address, dbms_random.value(1, 100) as joker 
    from employee 
   where joker>5 
order by joker asc

  select name, bday, address, dbms_random.value(1, 100) as joker
    from employee 
group by name, bday, address 
  having joker > 5 
order by joker asc

这可能是我的问题，如何使用joker列进行查询？

Answer 1

尝试：

Select * from
(select name, bday, address, dbms_random.value(1, 100) as joker 
from employee)
where joker>5 
order by joker asc

Answer 2

GOOD。之所以有用，是因为您可以按表达式对列表进行排序/分组/过滤，但是不能对在同一查询中给定表达式的名称进行分类/分组/过滤。通过将查询与对DBMS_RANDOM.VALUE的调用嵌套在一起，别名JOKER可用于外部查询中的ORDER BY子句。 –

ora-00904无效的标识符

2 个答案: