mysql - 如果低于 mySQL，则排除计数列

Question

我正在尝试查找每种类型所有者的工作时间总和，不包括 ExperienceLevel 为“初级”的员工的服务和少于 3 名成员的任何 ExperienceLevel 类型。我一直在努力解决这个问题，但无法得到答案......

表格：

OWNER ( OwnerID, OwnerName, OwnerEmail, OwnerType )
PROPERTY ( PropertyID, PropertyName, Street, City, State, Zip, OwnerID )
EMPLOYEE ( EmployeeID, LastName, FirstName, CellPhone, ExperienceLevel )
SERVICE ( PropertyID, EmployeeID, ServiceDate, HoursWorked )

我的最新查询：

SELECT OwnerType, SUM(HoursWorked) AS SumOfHoursWorked
 FROM EMPLOYEE, SERVICE, OWNER
 WHERE EMPLOYEE.EmployeeID = SERVICE.EmployeeID 
 AND EMPLOYEE.ExperienceLevel <> 'Junior'
 AND (SELECT COUNT(ExperienceLevel) > 2)

Answer 1

select 语句中的所有表之间都需要有连接条件，并且您只限定员工和服务之间的连接。

此外

where employee.employeeid = service.employeeid 

添加

and service.propertyid = property.propertyId 
and property.ownerid = owner.ownerid  

正如米海的评论所建议的

and employee.experiencelevel in (select experiencelevel from employee having count(*) > 2)

最后，如果对这些值进行分组，总和会更好。

group by ownertype;