SQL Server 新闻门户网站数据库设计与实现
create database sc;use sc;
create table Admin(
adminId int identity(201301,1)primary key,
adminName varchar(255) unique not null,
pswd varchar(255) not null
);
CREATE TABLE Category (
categoryId int identity(1,1) primary key,
categoryName varchar(255) unique NOT NULL,
counter int DEFAULT 0
);
create table Article(
articleId int identity(1,1) primary key,
title varchar(255) not null,
content ntext ,
time date not null,
categoryId int not null,
foreign key (categoryId) references Category(categoryId) on delete no action on update cascade
);
/*触发器 添加一条新闻，对应新闻项总数加一*/
create trigger articleInsert
onArticle
for Insert as
declare
@categoryId int
Begin
select @categoryId = categoryId
from inserted
update Category
set counter = counter + 1
where categoryId = @categoryId
End
/*触发器 删除一条新闻，对应新闻项总数减一*/
create trigger articleDelete
onArticle
for delete as
declare
@categoryId int
Begin
select @categoryId = categoryId
from deleted
update Category
set counter = counter - 1
where categoryId = @categoryId
End
文档来源：51CTO技术博客https://blog.51cto.com/u_15322177/3266607
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