Sql server sql中的求和列

我需要一点帮助， 基本上，我正在为酒店管理创建一个数据库， 请看一下我的问题。所以，现在，在最后，我想为可用的服务取一个总数，这就是我被困的地方。这里有人能帮我解决这个问题吗？如果我在什么地方错了，请告诉我，因为我还在学习Microsoft SQL。 提前谢谢

Create Database CustRoomBooking
use CustRoomBooking

drop table RoomsTypes
CREATE TABLE RoomTypes
(
ID int Not NULL,
type varchar(50) not NULL,
PRIMARY KEY (ID)
)

CREATE TABLE Pricing
(
service_ID int not NULL,
price int not null,
PRIMARY KEY(Service_ID)
)


drop table Rooms
create Table Rooms
(
ID int Not NULL,
floor int not NULL,
bed int not NULL,
roomType int not NULL,
roomPrice int not NULL, 
PRIMARY KEY (ID),
FOREIGN KEY (roomType) REFERENCES RoomTypes(ID),
FOREIGN KEY (roomPrice) REFERENCES Pricing(Service_ID)
)


Drop Table Customers
create Table Customers
(
ID int Not NULL,
name varchar(100) not NULL,
cnic varchar (13) not null,
age int not null,
phone varchar(11) not null,
gender varchar(6) not null,
PRIMARY KEY (ID)
)


drop table Booking
Create Table Booking
(
ID int not NULL,
room_ID int not NULL,
cust_ID int not NULL,
checkIN date not NULL,
checkOUT date not NULL,
booking_status varchar(100) not NULL,
booking_date date not NULL,
PRIMARY KEY (ID),
FOREIGN KEY (room_ID) REFERENCES Rooms(ID),
FOREIGN KEY (cust_ID) REFERENCES Customers(ID)

)

drop table Billing
Create Table Billing 
(
ID int NOT NULL,
room_ID int not NULL,
service_price int not NULL,
cust_ID int not NULL,
credit_card varchar(20) not NULL,
payment_date Date not NULL,
status varchar(50) not NULL, 

FOREIGN KEY (room_ID) REFERENCES Rooms(ID),
FOREIGN KEY (service_price) REFERENCES Pricing(service_ID),
FOREIGN KEY (cust_ID) REFERENCES Customers(ID)
)

CREATE TABLE Services
(
ID int not null,
service varchar (100),
price int not NULL,
PRIMARY KEY(ID),

FOREIGN KEY(price) REFERENCES Pricing(service_ID)

)

CREATE TABLE ServicesAvailed
(
ID int not null,
cust_ID int not NULL,
service int not NULL,
price int not NULL,

PRIMARY KEY(ID),
FOREIGN KEY(cust_ID) REFERENCES Customers(ID),
FOREIGN KEY(service) REFERENCES Services(ID),
FOREIGN KEY(price) REFERENCES Pricing(service_ID)
)

insert into ServicesAvailed
values
(1,1,1,1),
(2,1,2,2)


insert into RoomTypes
Values
(1,'Standard'),
(2,'Moderate '),
(3,'Deluxe ')

insert into Services
Values
(1,'Laundry',1),
(2,'Airport Transport',2),
(3,'Standard Room',3),
(4,'Moderate Room',4),
(5,'Deluxe Room',5)


insert into Pricing
Values
(1,1000),
(2,2000),
(3,2000),
(4,4000),
(5,6000)

insert into Rooms
Values
(1,0,2,1,3),
(2,0,2,1,3),
(3,1,3,2,4),
(4,1,3,2,4),
(5,2,4,3,5),
(6,2,4,3,5)

insert into Customers
Values
(1,'Hamza','12345',20,'98765','Male'),
(2,'Ahmed','12345',20,'98765','Male'),
(3,'Irfan','12345',20,'98765','Male')

Insert Into Booking
Values
(1,1,1,'2020-12-31','2021-1-1','Booked','2020-12-31'),
(2,2,2,'2020-12-31','2021-1-1','Booked','2020-12-31')

Insert Into Billing 
Values
(1,1,1,1,'5657446546','2020-12-31','Paid'),
(2,2,2,2,'5657446546','2020-12-31','Paid')

select * from Billing
select * from Booking
select * from Customers
select * from RoomTypes
select * from Rooms
select * from RoomPrices
select * from Booking
select * from Billing




select r.ID as RoomNumber,r.floor,r.bed,rt.*,p.price from Rooms r
inner join RoomTypes rt on r.roomType=rt.ID
inner join Pricing p on r.roomPrice=p.service_ID





select b.ID as BookingID,c.ID as CustomerID,c.name,b.booking_date,b.booking_status,b.checkIN,b.checkOUT, r.ID as roomID,r.floor,r.bed,rt.type,rp.price from Booking b
inner join Customers c on b.cust_ID=c.ID
inner join Rooms r on b.room_ID=r.ID
inner join RoomTypes rt ON r.roomType=rt.ID
inner join Pricing rp ON r.roomPrice= rp.service_ID 
where c.name='Hamza'


select * from Billing


select c.ID as CustomerID,c.name,r.ID as roomID,r.floor,r.bed,rt.type,rp.price from Billing b
inner join Customers c on b.cust_ID=c.ID
inner join Rooms r on b.room_ID=r.ID
inner join RoomTypes rt ON r.roomType=rt.ID
inner join Pricing rp ON r.roomPrice= rp.service_ID 

select sa.ID as NumberOFService,c.ID as CustomerID,c.name,s.service,p.price from ServicesAvailed sa
inner join Customers c on sa.cust_ID=c.ID
inner join Services s on sa.service=s.ID
inner join Pricing p on sa.price=p.service_ID

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我猜你的问题是你上次的查询没有包括房间本身的价格。在这种情况下，我将执行以下步骤：

向表[ServicesAvailed]中添加[charged_date]列，并将其包含在主键中，因为客户可能多次购买同一类型的服务

向[Booking]添加触发器，使用[checkIN]和[checkOUT]列在[ServicesAvailed]中创建实际为房价的条目。然后，您的最终查询将包括房间价格

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如果你不想在[Services AsvestEd]中的同一个嘘声中每天都有一行，你可以考虑一个额外的列（乘法器），它将把基本服务价格乘以一个因素（如果房间是一个日期）。如果需要，可以使用类似的逻辑来实现折扣等等。

MySQL和Microsoft SQL Server是不同的数据库产品。删除不相关的DBMS标记。