Table:
new_table
user_number | diff
2 | 0
1 | 28
2 | 32
1 | 40
1 | 53
1 | 59
1 | 101
1 | 105
2 | 108
2 | 129
2 | 130
1 | 144
|(result)
v
range | number of users
0-20 | 2
21-41 | 3
42-62 | 1
63-83 | 2
84-104 | 1
105-135| 0
136-156| 3
select t.range as [range], count(*) as [number of users]
from (
select case
when diff between 0 and 20 then ' 0-20'
when diff between 21 and 41 then ' 21-41'
when diff between 42 and 62 then ' 42-62'
when diff between 63 and 83 then ' 63-83'
when diff between 84 and 104 then ' 84-104'
when diff between 105 and 135 then ' 105-135'
else '136-156'
end as range
from new_table) t
group by t.diff
Error:
You have an error in your SQL syntax, near '[range], count(*) as [number of users]
from (
select case
when' at line 1
最佳答案
这是按范围分组的通用代码，因为执行 case 语句会变得非常麻烦。
“floor”函数可用于查找范围的底部(不是 Bohemian 使用的“round”)，并添加数量(下例中为 19)以查找范围的顶部。请记住不要与范围的底部和顶部重叠!
mysql> create table new_table (user_number int, diff int);
Query OK, 0 rows affected (0.14 sec)
mysql> insert into new_table values (2, 0), (1, 28), (2, 32), (1, 40), (1, 53),
(1, 59), (1, 101), (1, 105), (2, 108), (2, 129), (2, 130), (1, 144);
Query OK, 12 rows affected (0.01 sec)
Records: 12 Duplicates: 0 Warnings: 0
mysql> select concat(21*floor(diff/21), '-', 21*floor(diff/21) + 20) as `range`,
count(*) as `number of users` from new_table group by 1 order by diff;
+---------+-----------------+
| range | number of users |
+---------+-----------------+
| 0-20 | 1 |
| 21-41 | 3 |
| 42-62 | 2 |
| 84-104 | 1 |
| 105-125 | 2 |
| 126-146 | 3 |
+---------+-----------------+
6 rows in set (0.01 sec)
关于mysql - 在mysql中按范围分组，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/6687534/