带CTE的SQL Select

Question

What I'm trying to do is get the name of the city with biggest number of orders. Seems simple enough, yet when I run this code (I had to use CTEs), I get only the number of orders, no city name.

WITH CityOrder AS
(
    SELECT City 
    FROM Person.Address JOIN Sales.SalesOrderHeader 
        ON ShipToAddressID = AddressID
), 
CitiesOrders AS
(
    SELECT City, COUNT(City) AS "NoOfOrders"
    FROM CityOrder
    GROUP BY City
)
SELECT MAX("NoOfOrders") FROM CitiesOrders;

I tried to change last line to

SELECT City, MAX("NoOfOrders") FROM CitiesOrders;

But then, it shows all the cities with their orders. I'm pretty sure I'm not seeing some simple mistake. Any advice?

Answer 1

Order your results and take top 1 but with ties in case several cities have same number of orders:

...
SELECT TOP 1 WITH TIES * 
FROM CitiesOrders
ORDER BY NoOfOrders DESC

Answer 2

Try this!

select top 1 * from
(
SELECT City,count(1) as x 
    FROM Person.Address JOIN Sales.SalesOrderHeader 
        ON ShipToAddressID = AddressID
group by City
) order by x desc

Answer 3

WITH CityOrder AS
(
SELECT City 
    FROM Person.Address JOIN Sales.SalesOrderHeader 
    ON ShipToAddressID = AddressID
),  
CitiesOrders AS
(
SELECT City, COUNT(City) AS "NoOfOrders"
    FROM CityOrder
   GROUP BY City
)
SELECT * from CitiesOrders order by "NoOfOrders" desc limit 1;

Answer 4

you write perfect query but a little bit is missing there. You can use your query with Group by .

SELECT City, MAX("NoOfOrders") FROM CitiesOrders group by City