求一关于计算百分比的sql语句

[caikeji2003]

一个表字段如下
id num1 num2
1 12 15
2 21 16
3 14 17
……

求 1。【字段num1的总和】在【字段num1的总和＋字段num2的总和】中所占的百分比

2。筛选出【字段num1】在【num1＋num2之和】中所占比例大于（或小于）总比例的所有记录（一个语句实现）

[Liroyal]

1.select sum(num1) * 1.0 / (sum(num1) + sum(num2)) from table

[zlp321002]

1:
select round(sum(rum1)/(sum(rum1)+sum(rum2)),4)*100 from 表

[Liroyal]

2. select * from table where num1 * 1.0 / num2 > (select sum(num1) * 1.0 / (sum(num1) + sum(num2)) from table)

[jackluo1981]

1. select (sum(num1)+0.00001) / (sum(num1) + sum(num2)) from table
2. select (sum(num1)+0.00001) / (sum(num1) + sum(num2)) from table where
sum(num1)+0.00001) / (sum(num1) + sum(num2))>总比例

[jackluo1981]

2. select num1 / (num1 + num2) from table where num1 / (num1 + num2)>sum(num1)+0.00001) / (sum(num1) + sum(num2))