SQL查询来计算奇数和偶数的位数总和

Question

我需要一个SQL查询/函数，它将找出数位的总和，它出现在偶数位置和数字的总和位于奇数位置。

实施例：

如果号码是440065385：

x=4+0+6+3+5=18(x is holding sum of odd positions) 
y=4+0+5+8=17 (y holds the sum of even positions). 

感谢。

Answer 1

可以使用水平模仿迭代并连接通过以达到相同的

with iterate as 
(select level as i from dual connect by level <=25) 
select 
     table1.column1, 
     sum(decode(mod(iterate.i,2),0,substr(table1.column1,iterate.i,1))) sum_even, 
     sum(decode(mod(iterate.i,2),1,substr(table1.column1,iterate.i,1))) sum_old 
from table1 ,iterate 
where iterate.i <=length(table1.column1) 
group by table1.column1 

Answer 2

你可以用数字表加入你的表格，将所有数字拆分成若干行，然后分别计算赔率和位置数字。

with positions(position) as 
    (select level from dual connect by level <=25 
    ), 
digits as 
    (
    select 
     t1.v, 
     n.position , 
     cast(substr(t1.v ,length(t1.v) - n.position + 1, 1) as int) as digit 
    from my_table t1 left join positions n 
    on n.position <= length(t1.v) 
    ) 
select 
    v, 
    sum(case when mod(position,2)=0 then digit else 0 end) as evensum, 
    sum(case when mod(position,2)=1 then digit else 0 end) as oddsum 
from 
    digits 
group by 
    v 

测试Sql Fiddle，结果：

V   EVENSUM ODDSUM 
440065385 17  18