📄 sql.sql
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create table [user]
(
id int identity(1,1),
name varchar(20) not null,
sex char(2) not null,
age int,
department varchar(20),
borrowID varchar(20) not null,
primary key(borrowID)
)
go
create table book
(
id int identity(1,1),
title varchar(100) not null,
bookID varchar(20) not null,
type varchar(20) not null,
quantity int,
primary key(bookID)
)
go
create table borrowBook
(
id int identity(1,1),
borrowID varchar(20) not null,
beginTime datetime not null,
endTime as (beginTime+30),
bookID varchar(20) not null,
foreign key(borrowID) references [user](borrowID),
foreign key(bookId) references book(bookid)
)
s
CREATE trigger borrow
on borrowBook
for insert
as
begin
if (select max(quantity) from book where bookid=(select top 1 bookid from inserted))>0
begin
update book set quantity=quantity-1 where bookID=(select top 1 bookid from inserted)
end
else
rollback
end
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