Question

所以我有这个sql代码：

select stone_number,stone_size,stone_shape,stone_weight 
from stone
left Join stone_price stp on stp.id_stone = stone.id_stone
group by stone_number,stone_size,stone_shape,stone_weight 
having  avg(stp.price) < stp.price;

Sqldeveloper返回：不是表达式的组我仍然在我的代码中有group by。我的目标是得到价格高于所有宝石平均价格的石材。

Answer 1

select stone_number, stone_size, stone_shape, stone_weight 
from stone
left Join stone_price stp on stp.id_stone = stone.id_stone
group by stone_number, stone_size, stone_shape, stone_weight 
having (select avg(price) from stone_price) < max(stp.price)

您需要在having子句中的所有列上使用聚合函数。因此，如果您想获得至少一个奖品高于平均水平的宝石，您可以使用max()。如果所有都需要更高，请使用min()。

Answer 2

您可以使用窗口功能执行此操作：

select *
from (
  select stone_number,stone_size,stone_shape,stone_weight, 
         stp.price, 
         avg(stp.price) over () as avg_price
  from stone
    left Join stone_price stp on stp.id_stone = stone.id_stone
)  
where price > avg_price;

请注意，外连接表上的条件实际上将外连接转换为内连接。如果您还希望在stone_price中包含您需要

的行，那么这些行不匹配

where price is null
   or price > avg_price;

否则，您只需将left join更改为“普通”join

即可

另一个选项是简单的子选择：

select stone_number,stone_size,stone_shape,stone_weight, 
from stone
  left Join stone_price stp on stp.id_stone = stone.id_stone
where stp.price > (select avg(price) from stone_price);

Answer 3

一种方法是使用存储过程，您可以设置如下变量：

DECLARE @average_price INT
SET @average_price = (SELECT Avg(stone_price) from stone

然后在SELECT语句中

select stone_number,stone_size,stone_shape,stone_weight 
from stone
left Join stone_price stp on stp.id_stone = stone.id_stone
WHERE stone_price > @average_price

带有子句

3 个答案: