存储过程总结：①Cursor cursor is select * from batch_import_card;-- 显性游标，cursor 存储了所有数据 for bic in cursor LOOP -- 隐性游标，for in 循环cursor，每次取出一行，bic代表一行数据,循环开始 if--else if -- if-
--效率低 select * from (select rownum rn, d.* from table d )p where p.rn=10; select * from (select rownum rn, d.* from table d )p where p.rn between 10 and 20; --效率高 select * from (select rownum r...
示例1:剔除重复记录 表temp_b的记录：
执行如下SQL语句：
select * from ( select city_name, city_code, prov_id, row_number() over(partition by city_name order by 1) r from
