数据库设计时候的泛化问题 - V2EX
V2EX = way to explore
V2EX 是一个关于分享和探索的地方
现在注册
已注册用户请  登录
MySQL 5.5 Community Server
MySQL 5.6 Community Server
Percona Configuration Wizard
XtraBackup 搭建主从复制
Great Sites on MySQL
Percona
MySQL Performance Blog
Severalnines
推荐管理工具
Sequel Pro
phpMyAdmin
推荐书目
MySQL Cookbook
MySQL 相关项目
MariaDB
Drizzle
参考文档
http://mysql-python.sourceforge.net/MySQLdb.html
xevan
V2EX    MySQL

数据库设计时候的泛化问题

  •  
  •   xevan 2013-08-07 11:00:22 +08:00 4511 次点击
    这是一个创建于 4461 天前的主题,其中的信息可能已经有所发展或是发生改变。
    有两个表
    这个表是 信息表,是所有帖子的超类
    create table Message
    (
    mes_id varchar(20),
    user_id varchar(20) NOT NULL,
    parent_id varchar(20),
    content varchar(10000),
    noticed_user varchar(1000),
    primary key(mes_id),
    foreign key(user_id) references User
    on update cascade
    );

    这个表是 心愿表,由Message泛化而来
    create table Wish
    (
    wish_id varchar(20),
    yes_or_no integer,
    get_time varchar(20),#这里其实可以用time这个数据类型
    wanted_users varchar(1000),
    primary key(wish_id),
    foreign key(wish_id) references Message
    on delete cascade on update cascade
    );

    问题是我现在如果想插入一个心愿,我应该怎么插??
    2 条回复    1970-01-01 08:00:00 +08:00
    ekenchan
        1
    ekenchan  
       2013-08-07 11:24:40 +08:00
    如果你用hibernate的话可以用joined-subclass映射子类
    xevan
        2
    xevan  
    OP
       2013-08-07 11:55:28 +08:00 via iPhone   1
    @ekenchan 噢!没有用那些框架。就是单纯的mysql数据库。你说,我们做一个学校的信息共享平台,类似于论坛,有没有必要用ER图这种系统化的方法,还是直接建表来得快?
    关于     帮助文档     自助推广系统     博客     API     FAQ     Solana     901 人在线   最高记录 6679       Select Language
    创意工作者们的社区
    World is powered by solitude
    VERSION: 3.9.8.5 25ms UTC 21:37 PVG 05:37 LAX 14:37 JFK 17:37
    Do have faith in what you're doing.
    ubao msn snddm index pchome yahoo rakuten mypaper meadowduck bidyahoo youbao zxmzxm asda bnvcg cvbfg dfscv mmhjk xxddc yybgb zznbn ccubao uaitu acv GXCV ET GDG YH FG BCVB FJFH CBRE CBC GDG ET54 WRWR RWER WREW WRWER RWER SDG EW SF DSFSF fbbs ubao fhd dfg ewr dg df ewwr ewwr et ruyut utut dfg fgd gdfgt etg dfgt dfgd ert4 gd fgg wr 235 wer3 we vsdf sdf gdf ert xcv sdf rwer hfd dfg cvb rwf afb dfh jgh bmn lgh rty gfds cxv xcv xcs vdas fdf fgd cv sdf tert sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf sdf shasha9178 shasha9178 shasha9178 shasha9178 shasha9178 liflif2 liflif2 liflif2 liflif2 liflif2 liblib3 liblib3 liblib3 liblib3 liblib3 zhazha444 zhazha444 zhazha444 zhazha444 zhazha444 dende5 dende denden denden2 denden21 fenfen9 fenf619 fen619 fenfe9 fe619 sdf sdf sdf sdf sdf zhazh90 zhazh0 zhaa50 zha90 zh590 zho zhoz zhozh zhozho zhozho2 lislis lls95 lili95 lils5 liss9 sdf0ty987 sdft876 sdft9876 sdf09876 sd0t9876 sdf0ty98 sdf0976 sdf0ty986 sdf0ty96 sdf0t76 sdf0876 df0ty98 sf0t876 sd0ty76 sdy76 sdf76 sdf0t76 sdf0ty9 sdf0ty98 sdf0ty987 sdf0ty98 sdf6676 sdf876 sd876 sd876 sdf6 sdf6 sdf9876 sdf0t sdf06 sdf0ty9776 sdf0ty9776 sdf0ty76 sdf8876 sdf0t sd6 sdf06 s688876 sd688 sdf86