Question

我的任务是选择推销员的姓名和姓名，并计算他们在FireBird 2.5中在2010年销售的汽车数量。这是数据库：

Salesman(salesmanID:int primary key, salesmanName:char(20), SalesmanSurname:char(20))
sale (SalesDate:Date, SalesmanID:foreignkey to salesman)

我试过这个：

select s.count(*), sm.salesmanID, sm.salesmanName, sm.SalesmanSurname
from sale s inner join salesman on s.salesmanID=sm.salesmanID
where SalesDate between '1.1.2010' and '31.12.2010';

我得到的错误是：

Statement failed, SQLSTATE = 42000
Dynamic SQL Error
-SQL error code = -104
-Invalid expression in the select list (not contained in either an aggregate function or the GROUP BY clause)

Answer 1

以这种方式工作

SELECT
    count(*),
    sm.salesmanID,
    sm.salesmanName,
    sm.SalesmanSurname
FROM
    sale s
INNER JOIN salesman sm ON s.salesmanID = sm.salesmanID
WHERE
    s.SalesDate BETWEEN '1.1.2010'
AND '31.12.2010'
GROUP BY
    sm.salesmanID,
    sm.salesmanName,
    sm.SalesmanSurname

Answer 2

您使用的s.count(*)不是有效的语法。这可能是您收到错误的原因之一。

另外，我不会在任何表格上看到sm作为别名。这里发现了很多问题。

Answer 3

首先制作聚合（你错过了一个组），然后将结果与推销员表联系起来：

select s.salescount, s.salesmanID , sm.salesmanName, sm.SalesmanSurname from
(select count(*) as salescount, salesmanID
FROM sale where SalesDate between '1.1.2010' and '31.12.2010'
    group by salesmanID) as s inner join salesman sm on s.salesmanID=sm.salesmanID

如何选择其他有计数的东西

3 个答案: