[英]SQL Select Query with Join: How to Count a Certain Number of Occurences on non-primary Attribute without a Foreign Key
Using the following Tables: 使用下表:
CREATE TABLE CUSTOMERS
(customerID INT PRIMARY KEY,
customerFullName VARCHAR(20) NOT NULL,
customerStreet VARCHAR(40) NOT NULL,
customerState VARCHAR(15) NOT NULL,
customerCity VARCHAR(20) NOT NULL,
customerZip VARCHAR(15) NOT NULL);
CREATE TABLE VEHICLES
(vehicleVIN VARCHAR(25) PRIMARY KEY,
vehicleType VARCHAR(10) NOT NULL CHECK (lower(vehicleType) IN ('compact', 'midsize', 'fullsize', 'suv', 'truck')),
vehicleMake VARCHAR(15) NOT NULL,
vehicleModel VARCHAR(15) NOT NULL,
vehicleWhereFrom VARCHAR(20) NOT NULL CHECK (lower(vehicleWhereFrom) IN ('maryland','virginia','washington, d.c.')),
vehicleWholesaleCost DECIMAL(9,2) NOT NULL,
vehicleTradeID INT);
CREATE TABLE SALES
(saleID INT PRIMARY KEY,
grossSalePrice DECIMAL(9,2),
vehicleStatus VARCHAR(10) NOT NULL CHECK (lower(vehicleStatus) IN ('available', 'sold', 'pending')),
saleDate DATE,
saleMileage INT,
customerID INT,
salespersonID INT,
vehicleVIN VARCHAR(25),
CONSTRAINT SALES_FK1 FOREIGN KEY (customerID) REFERENCES CUSTOMERS(customerID),
CONSTRAINT SALES_FK2 FOREIGN KEY (vehicleVIN) REFERENCES VEHICLES(vehicleVIN));
I have built the following query to display the vehicleMake that was involved in the most sales and the customerFullName of all who purchased a vehicle of that make: 我建立了以下查询,以显示涉及最多销售额的vehicleMake和购买该品牌车辆的所有人的customerFullName:
SELECT VEHICLES.vehicleMake, CUSTOMERS.customerFullName
FROM SALES
JOIN CUSTOMERS on SALES.customerID = CUSTOMERS.customerID
JOIN(
SELECT SALES.vehicleVIN, VEHICLES.vehicleMake
FROM SALES
JOIN VEHICLES ON SALES.vehicleVIN = VEHICLES.vehicleVIN
GROUP BY SALES.vehicleVIN, VEHICLES.vehicleMake
HAVING COUNT(SALES.vehicleVIN) >= ALL
(SELECT COUNT(SALES.vehicleVIN)
FROM SALES
INNER JOIN VEHICLES ON SALES.vehicleVIN=VEHICLES.vehicleVIN
GROUP BY VEHICLES.vehicleMake))
VEHICLES ON SALES.vehicleVIN = VEHICLES.vehicleVIN
ORDER BY CUSTOMERS.customerFullName;
When I run this in my Oracle NOVA DB, I only get "no rows selected" as a result. 当我在Oracle NOVA DB中运行此程序时,结果仅是“未选择行”。 I suspect this is because the following clause is counting the number of occurrences that a vehicleVIN is sold, instead of counting the number of occurrences that a vehicleMake is sold.
我怀疑这是因为以下子句是在计算出售车辆VIN的次数,而不是在计算出售VehicleMake的次数。
HAVING COUNT(SALES.vehicleVIN) >= ALL
(SELECT COUNT(SALES.vehicleVIN)
FROM SALES
INNER JOIN VEHICLES ON SALES.vehicleVin=VEHICLES.vehicleVIN
GROUP BY VEHICLES.vehicleMake))
VEHICLES ON SALES.vehicleVIN = VEHICLES.vehicleVIN
ORDER BY CUSTOMERS.customerFullName;
How would I change this SELECT Count subquery to count the number of vehicleMake occurences instead of the number of vehicleVIN occurrences? 我将如何更改此SELECT Count子查询来计算vehicleMake出现的次数而不是vehicleVIN出现的次数? The output I'm looking for is:
我正在寻找的输出是:
vehicleMake customerFullName
CAR2 Bob Jim
CAR2 Jim Bob
CAR2 Steve France
CAR2 Tom Williams
CAR2 John Johnson
It should only display the vehicleMake of the vehicleMake that was sold the most, and the customerFullName of those who purchased any vehicle of that make. 它应该只显示销售量最大的vehicleMake中的vehicleMake,以及购买该品牌任何车辆的人的customerFullName。 Here is the link to SQL Fiddle if you want to see the Schema I've built: http://sqlfiddle.com/#!4/b0ac3a
如果要查看我已构建的架构,请参见以下SQL Fiddle的链接: http : //sqlfiddle.com/#!4/b0ac3a
http://sqlfiddle.com/#!4/b0ac3a/67 http://sqlfiddle.com/#!4/b0ac3a/67
WITH
tallied_sales AS
(
SELECT
SALES.*,
VEHICLES.vehicleMake,
COUNT(*) OVER (PARTITION BY VEHICLES.vehicleMake) AS vehicleMakeSales
FROM
SALES
INNER JOIN
VEHICLES
ON VEHICLES.vehicleVIN = SALES.vehicleVIN
),
ranked_sales AS
(
SELECT
tallied_sales.*,
RANK() OVER (ORDER BY vehicleMakeSales DESC) AS vehicleMakeSalesRank
FROM
tallied_sales
)
SELECT
*
FROM
ranked_sales
INNER JOIN
CUSTOMERS
ON CUSTOMERS.customerID = ranked_sales.customerID
WHERE
ranked_sales.vehicleMakeSalesRank = 1
;
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