Выберите запрос в SQL SERVER необходимо поддерживать

Question

У меня есть 3 такие таблицы:

- Employee_Table (Employee_Number, Employee_Name, Department_Number) 
    With Employee_Number is PRIMARY KEY, Department_Number is FOREIGN KEY;

- Employee_Skill_Table (Employee_Number, Skill_Code, Date Registered) 
    With PRIMARY KEY (Employee_Number, Skill_Code);

- Department (Department_Number, Department_Name) 
    With PRIMARY KEY (Department_Number); 

Как мне указать

the departments which have >= 3 employees

Помогите мне!

Answer 1

SELECT dept.department_name 
FROM employee_table emp 
INNER JOIN department dept ON emp.department_number= dept.department_number 
GROUP BY emp.department_number 
HAVING COUNT(emp.department_number) >= 3

Answer 2

Если вам нужны только департаменты, в которых работают более 3 человек, попробуйте этот запрос

SELECT d.Department_Name
FROM Department d 
JOIN Employee_Table e ON e.Department_Number = d.Department_Number
GROUP BY Department_Name
HAVING COUNT(*) >= 3