-----用户表
create table userInfo(
user_id integer not null,
user_name varchar2(10) not null,
user_pwd varchar2(10) not null,
constraint userInfo_pk primary key(user_id)
);
create table userInfo(
user_id integer not null,
user_name varchar2(10) not null,
user_pwd varchar2(10) not null,
constraint userInfo_pk primary key(user_id)
);
create table title(
title_id integer not null,
user_id integer not null,
title_name varchar2(50),
title_text varchar2(300),
title_date date,
constraint title_pk primary key(title_id),
constraint title_fk foreign key(user_id) references userInfo(user_id) ON DELETE CASCADE
);-----回帖表
create table content(
content_id integer not null,
title_id integer not null,
user_id integer not null,
content_text varchar2(300),
content_date date,
constraint content_pk primary key(content_id),
constraint content_title_id_fk foreign key(title_id) references title(title_id) ON DELETE CASCADE,
constraint content_user_id_fk foreign key(user_id) references userInfo(user_id) ON DELETE CASCADE
);
主题1 主题2 主题3
2009-11-1 5 1
2009-11-2 1 2 2
2009-11-3 5
2009-11-4 12 10
。
。
。我该怎么写sql语句啊,写几条啊,大牛,救救我啊