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SQL-聚合函数-1075.项目员工I

发布时间 2023-11-30 06:17:41作者: Offer多多

解题思路：

 

SELECT 
    Project.project_id AS project_id,
    ROUND(SUM(Employee.experience_years)/COUNT(Project.project_id), 2) AS average_years
FROM Project
LEFT JOIN Employee
ON Project.employee_id = Employee.employee_id
GROUP BY Project.project_id;