如何在MySQL中使用count函数的结果？

Question

我需要做一个查询计数有多少员工在有超过1名员工并与员工数量大于或等于6每个部门，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; 

这充满除了关于有部分的所有要求超过1名员工，有没有办法只执行代码的其余部分，从第一行返回2或更大的结果？

Answer 1

使用HAVING子句。请注意，在整个事情计算完毕后才会应用它。

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 ;