题解 | 分析员工在不同项目中的绩效表现以及所属部门的平均绩效情况

select employee_id,department_name ,performance_score
from (
    select department_id ,avg(performance_score ) as avg_score
    from employee_projects join department_info using(employee_id )
    group by department_id 
) temp  join department_info using(department_id )
 join employee_projects using(employee_id )
 where performance_score>avg_score
 order by employee_id;