Question

我有一个“订单”表：

ID  CustomerID  Freight
1      VINET      32.38
2      TOMPS      11.61
.        .          .
.        .          . 
.        .          .

我想只选择运费超过平均水平的那些customerID !!

SELECT CustomerID FROM Orders WHERE CustomerID IN(SELECT CustomerID,AVG(Freight) AVGFreight FROM Orders Group By CustomerID )

我知道到这里，但我怎么能比较运费和平均值呢？请帮助我谢谢

Answer 1

我假设客户每人都有1条记录。

<击> SELECT CustomerID 来自dbo.Orders 运费＆gt; =（SELECT @AvgFreight = AVG（运费）FROM dbo.Orders）

我不确定，如果这样可行的话。试试吧。
Upvote @ marc_s的回答，因为我的回答是基于它。

SELECT CustomerID
FROM dbo.Orders 
WHERE AVG(Freight) >= (SELECT AVG(Freight) FROM dbo.Orders)
GROUP BY CustomerID

Answer 2

这个怎么样：

SELECT CustomerID 
FROM dbo.Orders 
WHERE Freight >= (SELECT AVG(Freight) FROM dbo.Orders)
GROUP BY CustomerID

您选择的客户，所有客户的运费都大于表中所有运费的平均值。

Answer 3

CREATE TABLE Orders(
    ID int,
    CustomerId varchar(10),
    Freight money
);
INSERT INTO Orders Values(1,'VINET',10);
INSERT INTO Orders values(2,'VINET',10);
INSERT INTO Orders values(3,'TOMPS',12);
INSERT INTO Orders values(4,'TOMPS',11);

显示平均值：

Select CustomerId,avg(Freight)AvgFreight
from Orders
group by customerId

| CustomerId | AvgFreight | |------------+------------| | TOMPS | 11.50 | | VINET | 10.00 | |------------+------------|

将运费与平均值进行比较：

Select Orders.CustomerId 
from Orders,
(Select CustomerId,avg(Freight)AvgFreight
from Orders
Group by customerId)t
Where Orders.Freight > t.AvgFreight
And Orders.CustomerId = t.Customerid

| CustomerId | |------------| | TOMPS | |------------|

Answer 4

使用HAVING子句。

SELECT CustomerID
FROM Orders 
GROUP BY CustomerID 
HAVING AVG(Freight) > (SELECT AVG(Freight) FROM Orders)

在sql server 2005中使用AVG聚合函数

4 个答案: