求方法 效率要考虑
之前用拷贝的方法做
- SQL code
create table tmp as (select distinct * from salgrade);drop table salgrade;create table salgrade as (select * from tmp);drop table tmp;select * from salgrade;
被点评效率太低
有改进什么办法
------解决方案--------------------
create table tmp as (select distinct * from salgrade);drop table salgrade;create table salgrade as (select * from tmp);drop table tmp;select * from salgrade;