此SQL查询有什么问题

Question

I need to find what bad with this SQL:

SELECT DepartmentName, COUNT(*) 
FROM employee,department 
WHERE employee.DepartmentID = department.DepartmentID 
GROUP BY DepartmentName
WHERE COUNT(*)>1

I think the problem in COUNT(*) beacause it return the count of all rows. So how I think the property sql will be without where statement. Help me I not good in SQL.

Answer 1

You have to use having cluase instead of where at the end of the statement:

SELECT DepartmentName, COUNT(*) 
FROM employee,department 
WHERE employee.DepartmentID = department.DepartmentID 
GROUP BY DepartmentName
having COUNT(*)>1

Answer 2

SELECT DepartmentName, COUNT(*) AS count
FROM employee,department 
WHERE employee.DepartmentID = department.DepartmentID 
GROUP BY DepartmentName
HAVING count>1;