建表之 查询 select
查询要素
查哪张表的数据
查哪些列
mysql> select name,company,salary from class where id=6; +------+---------+---------+ | name | company | salary | +------+---------+---------+ | 老三 | 新浪 | 6300.00 | +------+---------+---------+
查所有数据,
select * from class
* 代表所有行,所有列,表名后面又不加where条件,则选所有行,所有列