sql加入where子句

Question

有两个表 - 一个包含员工详细信息，另一个包含订单详细信息。

我如何找到在特定日期没有下订单的员工的姓名？

我使用左外连接，我的代码是这样的

SELECT 
    emp.FirstName+' '+emp.LastName AS 'FullName', emp.employeeid 
FROM Employee emp 
    INNER JOIN Orders oON emp.EmployeeID=o.EmployeeID 
WHERE 
    o.OrderDate NOT IN (SELECT o.OrderDate FROm Orders o WHERE o.OrderDate='4/4/1997') 
GROUP BY 
    emp.FirstName+' '+emp.LastName, emp.employeeid 

但问题是，它把所有的人在列表中.......请帮助我，请其紧迫

Answer 1

SELECT FirstName + ' ' + LastName AS 'FullName', 
     employeeid 
FROM Employee 
where EmployeeID not in (select EmployeeID 
         from Orders 
         where OrderDate = '1997-04-04') 

Answer 2

的一种方法是使用不存在

SELECT 
    emp.FirstName+' '+emp.LastName AS 'FullName', emp.employeeid 
FROM Employee emp 
where not exists 
    (select * from Orders o ON where emp.EmployeeID=o.EmployeeID 
     and o.OrderDate='4/4/1997' 
    ) 

Answer 3

SELECT emp.FirstName+' '+emp.LastName AS 'FullName', emp.employeeid 
FROM Employee emp LEFT JOIN Orders o 
ON emp.EmployeeID=o.EmployeeID And o.OrderDate='4/4/1997' 
where o.EmployeeID is null 
GROUP BY emp.FirstName+' '+emp.LastName, emp.employeeid 

试试这个。应该管用。和评论答案，因为我不能在我的本地测试...