总结: mySQL 数据库放在装MySQL/data文件夹里。 *.frm 是表定义文件,*.myd是数据文件,*.myi 是索引文件。 早上的时候装了sqlyog 和sqlfront玩了一下,我个人觉得sqlyog比较好玩,具体的读者下载两个去玩玩就知道了。自学的过程中发现和学习到了很多,比如刚开始让我一直很苦恼的怎么我修改完数据后还是不能在同一个窗口看table data !这样的话我就要一直select*from account才会跳出来, 其实明白英语的话也大有帮助!把表点开自然就可以了,你要看哪个表,你肯定要确认是哪个表啦!! 这个界面比较简单, 运行当前还有运行全部。 不过有一点需注意!但你运行多个语句的时候,之间必须用分号隔开!还有个多表查询的链接地址挺具体的分享一下http://www.dedecms.com/knowledge/data-base/sql-server/2012/0709/2872.html
select * from account
select * from account limit 2,4
update account set code='888' where password=600
insert into account values('444',222,222,22)
insert into account(code,password,money) values('77',88,88)
delete from account where money=220
alter table account add column age double;
alter table account modify column age int
alter table account drop column age
select min(money) zuixiao from account
select count(code) shumu from account
select sum(money) qian from account
select avg(money) pjqian from account
select * from account
group by password; /*注意group by 会 去除重复项*/
select * from account
order by money desc
select * from account
order by money asc /*desc 为降序,asc为升序(默认)*/
select distinct money from account
select * from account
group by money asc
having password>=300account2
select account.money,account.password,account.code
from account,account2
where account.code = account2.code
insert into account2 values('241',200,3000)