//组合单体
//项目标识 单体编号 单体主键
//1 SJ 123
//1 SJ 456
//1 SJ 789
//1 SC 222
//2 SC 333
//最后输出的格式：
//项目标识 串
//1 SJ:123,456,789;SC:222;
//2: SC:333;
纯的sql语句， 非存储过程
------解决方案--------------------------------------------------------
示例：
db2中关于递归(with)的使用
因为有人问及，这边简单的再探讨一下
-------------------
1.创建测试表
create table zxt_test
( id varchar(10),
ivalue varchar(20),
iname varchar(20)
)
commit;
-----------
2.插入测试语句
insert into zxt_test values('1','aa','x'),('2','bb','x'),('3','bb','x'),('1','bb','y'),('2','bb','y'),('3','bb','y');
commit;
---------------
3.查看数据
select * from zxt_test;
1 'aa' 'x'
2 'bb' 'x'
3 'bb' 'x'
1 'bb' 'y'
2 'bb' 'y'
3 'bb' 'y'
----------------
4.with 的写法！
with
s as (
select row_number()over(partition by iname order by id) id1,
row_number()over(partition by iname order by id) id2,
ivalue,iname from zxt_test
)
,
t(iname,id1,id2,ivalue) as
(
select iname,id1,id2,cast(ivalue as varchar(100)) from s where id1 =1 and id2=1
union all
select t.iname,t.id1+1,t.id2,cast(s.ivalue||','||t.ivalue as varchar(100))
from s, t
where s.id2=t.id1+1 and t.iname = s.iname
)
select iname,ivalue from t where t.id1= (select max(id1) from s where s.iname = t.iname);
5.结果如下：
'x' 'bb,bb,aa'
'y' 'bb,bb,bb'
------解决方案--------------------------------------------------------
百度里：db2 with 递归