如果多個記錄的長度相同，則選擇單個記錄

Question

我正在嘗試在HackerRank上解決此問題

我試過這個查詢：

select city, length(city) from station 
where length(city) = (select max(length(city)) from station)
      or length(city) = (select min(length(city)) from station)
order by
length(city) ASC,city ASC;

運行上面的查詢后，我得到以下結果：

Amo 3 
Lee 3 
Roy 3 
Marine On Saint Croix 21

我的問題是：我只想選擇Amo ＆ Marine On Saint Croix 。 沒有其他人。 如何實現呢？

提前致謝

Answer 1

您可以嘗試選擇限制為1的最小和最大長度的城市並合並嗎？

select city, length(city) from station 
where  length(city) = (select max(length(city)) from station)
Limit  1
UNION
select city, length(city) from station 
where  length(city) = (select min(length(city)) from station)
Limit  1

Answer 2

這是有效的正確查詢：

 (SELECT city, LENGTH(city) AS length FROM station
ORDER BY LENGTH(city), city
LIMIT 1) UNION 

(SELECT city, LENGTH(city) AS length FROM station
ORDER BY LENGTH(city) DESC, city
LIMIT 1)