第二章:排序.限制查询行 一.order by子句 1.order by排序规则 (1)asc,升序排列,默认取值 (2)desc,降序排列 (3)order by是select命令的最后一个子句 select last_name,salary,dept_id from s_emp order by salary; select last_name,salary,dept_id from s_emp order by salary asc; select last_name,salary,dep…