SQL多表操作

Create database News
go
use News
go
create table Category
(
    CategoryID int identity(1,1) primary key not null,
    CategoryName varchar(20)
)
go
create table News
(
    NewsID int identity(1,1) primary key not null,
    NewsContent varchar(200),
    CreateTime dateTime default getDate(),
    FKCategoryID int
)
go
alter table News
add foreign key(FKCategoryID) references Category(CategoryID)
go
create table Comment
(
    CommentID int identity(1,1) primary key not null,
    CommentContent varchar(200),
    CreateTime datetime default getDate(),
    FKNews int
)
go
alter table Comment
add foreign key(FKNews) references News(NewsID)
go