Question

我需要做一个查询，计算每个部门有多少员工，员工人数超过1人，员工人数为6或更高，我有：

 Select DepartmentName, count(EmployeeNumber) as "Number of Employees"
 From department d, employee e
 Where d.DepartmentName = e.Department and e.EmployeeNumber <=6 
 Group by d.DepartmentName;

除了关于拥有超过1名员工的部分之外，这还满足所有要求，是否有办法仅对第一行返回2或更高的结果执行其余代码？

Answer 1

使用HAVING子句。请注意，它是在计算整个事物后应用的。

Select DepartmentName, count(EmployeeNumber) as "Number of Employees"
From department d, employee e
Where d.DepartmentName = e.Department and e.EmployeeNumber <=6 
Group by d.DepartmentName HAVING count(EmployeeNumber) > 1;

Answer 2

试试这个

    Select DepartmentName, count(EmployeeNumber) as "Number of Employees"
    From department d, employee e
    Where d.DepartmentName = e.Department  
    Group by d.DepartmentName and e.EmployeeNumber <=6
    HAVING count(EmployeeNumber) > 1 ;

如何在MySQL中使用count函数的结果？

2 个答案: