得到这个SQL:MySQL的归国最低邮政编码
SELECT DISTINCT(LocCity), LocZipCode FROM exp_course_events order by LocCity
和这样的数据:
INSERT INTO `exp_course_events` (`LocCity`, `LocZipCode`) VALUES
('Aguadilla', '00602'), ('Akron', '44300'),('Akron', '44333'),
('Albany', '12205'), ('Albuquerque', '87102'),
('Albuquerque', '87109'), ('Austin', '78741'),
('Austin', '78753'), ('Austin', '78757'),
('Bend', '97701'), ('San Antonio', '78200'),
('San Antonio', '78201'),
....
('San Antonio', '78207');
需要为LocZipCode只返回一个值,每个LocCity,prefereable最低数量LocZipCode 为LocCity。
这是导致我想:
Aguadilla, 00602
Akron, 44300
Albany, 12205
Albuquerque, 87102
Austin, 78741
Bend, 97701
San Antonio, 78200
San Diego, 92108
San Francisco, 94111
San Juan, 00926
Santa Clara (San Jose), 95054
Springdale, 72762
Springfield, 62703
St. Louis. 63105
Visalia, 993291
Waco, 76705
Warwick, 02886
Waukesha, 53186
West Chester, 45069
West Des Moines, 50300
1对于组由链接。请注意,'order by'子句在MySQL中并不是严格需要的(尽管它看起来不错),因为DB已经按升序排列了“group by”的输出。 – Johan