Adventure for SQL Query

Question

我的任务是找到在两个部门工作过的员工的名字，我觉得我的格式是不正确的，因为它只显示了1个结果，而它应该返回4个结果，如果有人可以查看它，并让我知道如果我有一些语法错误，将非常感谢。

SELECT P.FirstName,LastName, COUNT(D.DepartmentID) as Departments
FROM HumanResources.EmployeeDepartmentHistory D
INNER JOIN Person.Person P ON P.BusinessEntityID = D.DepartmentID 
GROUP BY P.FirstName,LastName
HAVING COUNT(DepartmentID)=2

Answer 1

ON P.BusinessEntityID = D.DepartmentID -不会给出合理的结果尝试ON P.BusinessEntityID = D.BusinessEntityID