MYSQL 在执行 GROUP BY 和从 4 个数据库表中获取数据时遇到问题

Question

我有 4 个数据库表 Rental Car Company Database、Rental Car Details Database、Rental Car Rates Database 和 Booked Car Database。

有多家租车公司和地点有多辆汽车，每辆汽车的费率范围不同，

我想做的是查询所有这些数据库，找出哪些位置只有 03/04/22 - 03/10/22 可用的卡车。

我希望每个位置都显示每个位置有多少卡车可用，以及最低每日费率和最高每日费率。

问题是每辆卡车都有不同的价格，所以当我按位置进行 GROUP BY 时，当有两辆卡车可用时，它只给出一辆卡车的高价和低价。我的低点应该是我搜索的日期中两者中最低的日率，高点应该是两者中最高的日率。

我用下面的数据和代码得到的结果是：

Location	CarCount	Type	RentalCarCompanyName	lowrate	Highrate
LosAngeles	1	Truck	Car Lux	281	281
NewYork	2	Truck	Discount Car Rental	125	125

我想得到的是：

Location	CarCount	Type	RentalCarCompanyName	lowrate	Highrate
LosAngeles	1	Truck	Car Lux	281	281
NewYork	2	Truck	Discount Car Rental	125	169

我有四个数据库表如下

租车公司数据库 Table 姓名：（地理位置）

Location	Address	CompanyName
NewYork	Queens, NY 11430	Discount Car Rental
LosAngeles	1 World Way, Los Angeles, CA 90045	Car Lux

租车详情数据库 Table 姓名：（汽车）

Location	Car	Type
NewYork	NYCar1	Truck
NewYork	NYCar2	Truck
NewYork	NYCar3	Car
NewYork	NYCar4	Truck
LosAngeles	LACar1	Truck
LosAngeles	LACar2	Truck
LosAngeles	LACar3	Truck
LosAngeles	LACar4	Van

租车费率数据库 Table 姓名：（价格）

Car	fromdate	todate	dayrate
NYCar1	2022-01-01	2022-04-01	199
NYCar1	2022-04-01	2022-07-01	499
NYCar1	2022-07-01	2022-12-31	300
NYCar2	2022-01-01	2022-04-01	125
NYCar2	2022-04-01	2022-07-01	399
NYCar2	2022-07-01	2022-12-31	200
NYCar3	2022-01-01	2022-04-01	169
NYCar3	2022-04-01	2022-07-01	267
NYCar3	2022-07-01	2022-12-31	250
NYCar4	2022-01-01	2022-04-01	169
NYCar4	2022-04-01	2022-07-01	267
NYCar4	2022-07-01	2022-12-31	250
LACar1	2022-01-01	2022-04-01	281
LACar1	2022-04-01	2022-07-01	267
LACar1	2022-07-01	2022-12-31	267
LACar2	2022-01-01	2022-04-01	300
LACar2	2022-04-01	2022-07-01	250
LACar2	2022-07-01	2022-12-31	267
LACar3	2022-01-01	2022-04-01	500
LACar3	2022-04-01	2022-07-01	700
LACar3	2022-07-01	2022-12-31	400
LACar4	2022-01-01	2022-04-01	500
LACar4	2022-04-01	2022-07-01	700
LACar4	2022-07-01	2022-12-31	400

订车数据库 Table 姓名：（预订）

Car	ArrivalDate	DepartureDate	Name
NYCar1	2022-03-01	2022-03-19	Mike Smith
LACar2	2022-03-08	2022-03-16	Joe Luck
LACar3	2022-03-05	2022-03-25	Kelly Johnson

下面是我试过的代码

SELECT Cars.Location, COUNT(Cars.Location) AS CarCount, Cars.Type,
        (SELECT CompanyName
        FROM geolocations
        WHERE geolocations.Location = Cars.Location) AS RentalCarCompanyName,
                        
        (SELECT MIN(dayrate)
        FROM prices
        WHERE Car = Cars.Car AND fromdate <= '2022-03-14' AND DATE_ADD(todate, INTERVAL 1 DAY) > '2022-03-10' LIMIT 1) AS lowrate,
                       
        (SELECT MAX(dayrate)
        FROM prices
        WHERE Car = Cars.Car AND fromdate <= '2022-03-14' AND DATE_ADD(todate, INTERVAL 1 DAY) > '2022-03-10' LIMIT 1) AS highrate                  
FROM Cars
WHERE Car NOT IN (
    SELECT Car
    FROM      bookings
    WHERE      (
        ArrivalDate <= '2022-03-14' AND
        DepartureDate > '2022-03-10'
    ) 
) AND Cars.Type = 'TRUCK'                
GROUP BY Location  
ORDER BY Location ASC

我有一个 fiddle 已加载数据

Answer 1

这是您更新后的查询

SELECT 
  `cars`.`Location`, 
  COUNT(`cars`.`Location`) AS CarCount, 
  `cars`.`Type`, 
  `geolocations`.`CompanyName`, 
  MIN(`prices`.`dayrate`) AS lowrate, 
  MAX(`prices`.`dayrate`) AS highrate 
FROM 
  `cars` 
  JOIN `geolocations` ON `cars`.`Location` = `geolocations`.`Location` 
  JOIN `prices` ON `cars`.`Car` = `prices`.`Car` 
WHERE 
  `cars`.Car NOT IN (
    SELECT 
      Car 
    FROM 
      bookings 
    WHERE 
      (
        ArrivalDate <= '2022-03-14' 
        AND DepartureDate > '2022-03-10'
      )
  ) 
  AND Cars.Type = 'TRUCK' 
  AND `prices`.`fromdate` <= '2022-03-14' 
  AND DATE_ADD(todate, INTERVAL 1 DAY) > '2022-03-10' 
GROUP BY 
  Location 
ORDER BY 
  Location ASC

MYSQL 在执行 GROUP BY 和从 4 个数据库表中获取数据时遇到问题

MYSQL Having trouble doing a GROUP BY and getting data from 4 database tables

mysql

join

group-by

subquery