我有一个这样的表:
CITY QNT EXP RATE
LONDON 60 6 900
LONDON 35 8 337
LONDON 24 6 300
LONDON 22 6 266
BIRMINGHAM 22 6 266
NEWYORK 69 19 263
LONDON 21 6 250
ROME 24 7 242
BIRMINGHAM 24 7 242
BIRMINGHAM 24 7 242
LONDON 20 6 233
BIRMINGHAM 23 7 228
STUTTGART 29 9 222
LONDON 19 6 216
STUTTGART 25 8 212
PARIS 31 10 210
STUTTGART 34 11 209
STUTTGART 34 11 209
BIRMINGHAM 18 6 200
BIRMINGHAM 18 6 200
NEWYORK 18 6 200
BIRMINGHAM 17 6 183
LONDON 19 7 171
MUNICH 16 6 166
PARIS 21 8 162
STUTTGART 39 15 160
BARCELONA 18 7 157
LONDON 18 7 157
ROME 33 13 153
BARCELONA 15 6 150
PARIS 25 10 150
ROME 20 8 150
PARIS 25 10 150
ROME 20 8 150
LONDON 15 6 150
MUNICH 15 6 150
BIRMINGHAM 15 6 150
NEWYORK 15 6 150
LONDON 17 7 142
MUNICH 17 7 142
这是我的 sql 命令:
select CITY, QNT, EXP, (QNT-EXP)*100/EXP as RATE
from tbl_city
order by RATE desc
我想按城市对这些结果进行分组。但我做不到。我希望 top5 行变化最大。
结果应该是这样的:
LONDON 60 6 900
BIRMINGHAM 22 6 266
NEWYORK 69 19 263
ROME 24 7 242
STUTTGART 29 9 222
最佳答案
这是来自MySQL 5.6。
select CITY, QNT, EXP, (QNT-EXP)*100/EXP as RATE
from tbl_city GROUP BY CITY
order by RATE desc LIMIT 5
在此链接中测试:http://www.sqlfiddle.com/#!9/3f1ea1/1
这是来自MS SQL Server 2017
select TOP 5 f.CITY, f.QNT, f.EXP, x.RATE
from (
select CITY, MAX((QNT-EXP)*100/EXP) as RATE
from tbl_city GROUP BY CITY
) as x inner join tbl_city as f on f.CITY = x.CITY
and ((f.QNT-f.EXP)*100/f.EXP) = x.RATE
ORDER BY RATE DESC;
关于mysql - 选择前 5 个分组依据和排序依据,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/49684691/