SQL查询部门详细信息、人数和平均工资

要查询各个部门的详细信息以及部门人数、部门平均工资，可以使用以下SQL语句：\n\nSELECT \n department.department_id, \n department.department_name, \n COUNT(employee.employee_id) AS department_size, \n AVG(employee.salary) AS average_salary\nFROM \n department \n INNER JOIN employee ON department.department_id = employee.department_id\nGROUP BY \n department.department_id, \n department.department_name