select emp_no, count(emp_no) as t from salaries group by emp_no having t > 15;
用到了 group by進行emp_no的分組
同時用到了having 即在結果中進行過濾
select emp_no, count(emp_no) as t from salaries group by emp_no having t > 15;
用到了 group by進行emp_no的分組
同時用到了having 即在結果中進行過濾