好记性不如烂笔头

创建表、删除表、插入数据、更新数据、删除数据、添加注释、修改注释、修改表名、修改字段、新增字段、删除字段1、创建表CREATE TABLE person( id varchar2(20) primary key, name varchar2(50 char) not null, age number(3), crt_date timestamp(6));...

下面直接上示例：select t.* from (select row_number() over(partition by tor.order_name order by tor.order_id desc) rn, tor.* from tc_order tor) t where t.rn = 1;tc_order：表名order_name：分组列名order_id：排序...