如何選擇按範圍分組的值的計數

Question

冰雹，堆疊！

我需要選擇按範圍分組的值的計數。

爲了舉例說明，假設我有一個表columm以下值：1,2,4,5,6,8,9,11,13,16

然後，我想retreave他們的數量在5範圍內，像這樣：

From 0 to 4 there is 3 values (1,2,4) 
From 5 to 9 there is 4 values (5,6,8,9) 
From 10 to 14 there is 2 values (11,13) 
From 15 to 19 there is 1 values (16) 

而且等等......

我該如何在查詢中做到這一點？

Answer 1

也許這是你想要什麼：

SELECT 
    5 * (n div 5) as 'from', 
    5 * (n div 5) + 4 as 'to', 
    COUNT(*) 
FROM yourtable 
GROUP BY n div 5; 

爲您的樣品此查詢給你

+------+------+----------+ 
| from | to | count(*) | 
+------+------+----------+ 
| 0 | 4 |  3 | 
| 5 | 9 |  4 | 
| 10 | 14 |  2 | 
| 15 | 19 |  1 | 
+------+------+----------+ 
4 rows in set (0.00 sec) 

Answer 2

一種方法是總和+情況下的做法：

select sum(case when col1 between 0 and 4 then 1 end) 
,  sum(case when col1 between 5 and 9 then 1 end) 
,  sum(case when col1 between 10 and 14 then 1 end) 
... 
from YourTable 

另一種方法是有一個範圍表，填寫，如：

start end 
0  4 
5  9 
10  14 

然後，您可以：

select r.start 
,  r.end 
,  count(case when yt.col1 between r.start and r.end then 1 end) 
from YourTable yt 
cross join 
     RangeTable r 
group by 
     r.start 
,  r.end 

Answer 3

計算一個可以分組的值。在這種情況下，你只需要5分的價值得到這一結果：

select value/5 as Group, count(*) as Cnt 
from TheTable 
group by value/5 

這會給你的結果是這樣的：

Group Cnt 
0  3 
1  4 
2  2 
3  1 

Answer 4

select 
val/5 as grp, 
case val/5 
when 0 then ' 0 to 5' 
when 1 then ' 5 to 10' 
when 2 then '10 to 15' 
when 3 then '15 to 20' 
end 
as grpname, 
count(distinct val) as cnt 
from 
(
select 1 as val 
union select 2 
union select 4 
union select 5 
union select 6 
union select 8 
union select 9 
union select 11 
union select 13 
union select 16 
) a 
group by 
val/5 

Answer 5

如何

for(i=MIN_OF_TABLE-1;i<=MAX_OF_TABLE;$i+=RANGE){ 
    SELECT COUNT(`VALUE`),GROUP_CONCAT(`VALUE`) FROM `TABLE` WHERE `VALUE`>i AND `VALUE`<=i+RANGE; 
} 

這將讀取包含您在行中顯示的信息的行=）