単一照会としてマージ

Question

STATIONの2つの都市と、それぞれの長さ（名前の中の文字数）と同様に、最短および最長の都市名を照会します。複数の市区町村がある場合は、アルファベット順に並んで最初の市町村を選択します。

SELECT CITY,CHAR_LENGTH(CITY) AS CHARLENGTH 
FROM STATION 
ORDER BY CHARLENGTH ASC 
LIMIT 1; 

SELECT CITY,CHAR_LENGTH(CITY) AS CHARLENGTH 
FROM STATION 
ORDER BY CHARLENGTH DESC 
LIMIT 1; 

Answer 1

これはなんですか？

##DROP TABLE STATION; 
CREATE TABLE STATION (CITY VARCHAR(100)); 
INSERT INTO STATION VALUES ('aaaaaaa'); 
INSERT INTO STATION VALUES ('bbbbbbb'); 
INSERT INTO STATION VALUES ('cccc'); 
INSERT INTO STATION VALUES ('dd'); 
SELECT * 
FROM 
(SELECT CITY,CHAR_LENGTH(CITY) AS CHARLENGTH FROM STATION ORDER BY CHARLENGTH ASC, CITY LIMIT 1) A 
UNION ALL 
SELECT * FROM 
(SELECT CITY,CHAR_LENGTH(CITY) AS CHARLENGTH FROM STATION ORDER BY CHARLENGTH DESC, CITY LIMIT 1) B 

出力：

CITY CHARLENGTH 
1 dd 2 
2 aaaaaaa 7