使用COUNT和GROUP BY进行查询

Question

第一张表：员工

+------------+-----------+----------+-----+--------+--------+-------+
| EmployeeID | FirstName | LastName | Age | Gender | Salary | JobID |
+------------+-----------+----------+-----+--------+--------+-------+

第二张表： JobTitle

+-------+----------+----------------+--------+
| JobID | JobTitle | JobDescription | Status |
+-------+----------+----------------+--------+

编写一个SQL查询来统计所有员工和GROUP BY年龄和性别。 （输出显示别名）

我已完成以下查询：

SELECT COUNT(EmployeeID) AS Number_Of_Employees
FROM Employee
GROUP BY Age, Gender;

SELECT COUNT(*) AS 'Total_Employees'
FROM Employee
WHERE Gender = 'M' OR Gender= 'F'
GROUP BY Age, Gender;

这是两个查询的结果：

Answer 1

我想我找到了答案。我最终运行了这个查询，我认为它有效。

SELECT Age, Gender, 
COUNT(EmployeeID) AS Total_Employee
FROM Employee
GROUP BY Age, Gender;