题解 | #统计出当前各个title类型对应的员工当前薪水对应的平均工资#
统计出当前各个title类型对应的员工当前薪水对应的平均工资
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select t.title, avg(s.salary) from titles t join salaries s using (emp_no) where s.to_date = '9999-01-01' and t.to_date = '9999-01-01' group by t.title order by avg(s.salary)