摘要:
高级查询一:分组查询 1、group by select * from car group by powers; | num | d_id | name | age | sex | homeaddr | | 1 | 1001 | 张三 | 26 | 男 | beijinghdq|| 2 | 1002 阅读全文
摘要:
1、最简单查询select * from car;2、查询指定列select name,oil,powers from car;3、对查出的列名修改名字select name as '车名',oil as '油量',powers as '动力' from car;4、按条件查询select name 阅读全文