create table name_age(name varchar2(20) not null primary key,age integer);
问题：查询出各年龄段的人数
1.显示如下
10-19 5
20-29 7
30-39 2
. .
. .
. .
2.显示如下
10-19 20-29 30-39 ...
5 7 2 ...
11-20 5
21-30 7
31-40 2
. .
1,select decode(trunc(age/10),0,'0-10',1,'10-19',....),count(*) numfrom name_agegroup by trunc(age/10)2,select sum(decode(trunc(age/10),0,1,0)) '0-9',select sum(decode(trunc(age/10),1,,1,0)) '10-19',.....from name_age3,select decode(trunc((age-1)/10),0,'0-10',1,'11-20',....),count(*) numfrom name_agegroup by trunc((age-1)/10)
