突然想問個問個關於CTE的問題
create table #bom(mother_no varchar(10),child_no varchar(10),bo_qty decimal(20,4))--母料號,子料號,用量
insert into #bom (mother_no,child_no,bo_qty)
select 'A','B',3 union all
select 'A','C',2 union all
select 'B','E',3 union all
select 'B','G',2 union all
select 'B','H',4 union all
select 'E','F',2
create table #bom(mother_no varchar(10),
child_no varchar(10),
bo_qty int)
insert into #bom(mother_no,child_no,bo_qty)
select 'A','B',3 union all
select 'A','C',2 union all
select 'B','E',3 union all
select 'B','G',2 union all
select 'B','H',4 union all
select 'E','F',2
with t as
(select a.mother_no,a.child_no,a.bo_qty,a.mother_no 'max_mother_no',1 'lv'
from #bom a
where not exists(select 1 from #bom b where b.child_no=a.mother_no)
union all
select d.mother_no,d.child_no,d.bo_qty*c.bo_qty,c.max_mother_no,c.lv+1 'lv'
from t c
inner join #bom d on c.child_no=d.mother_no
)
select max_mother_no '母版料號',
child_no '子版料號',
bo_qty '用量',
lv 'Bom階層',
case when not exists(select 1 from #bom e
where e.mother_no=t.child_no) then 'Y' else 'N' end '是否為低階物料'
from t
/*
母版料號 子版料號 用量 Bom階層 是否為低階物料
---------- ---------- ----------- ----------- -------
A B 3 1 N
A C 2 1 Y
A E 9 2 N
A G 6 2 Y
A H 12 2 Y
A F 18 3 Y
(6 row(s) affected)
*/
FROM a1 a
[解决办法]
create table #bom(mother_no varchar(10),child_no varchar(10),bo_qty decimal(20,4))--母料號,子料號,用量
insert into #bom (mother_no,child_no,bo_qty)
select 'A','B',3 union all
select 'A','C',2 union all
select 'B','E',3 union all
select 'B','G',2 union all
select 'B','H',4 union all
select 'E','F',2
;with sel as(
select mother_no,child_no,bo_qty,1 as lev
from #bom where mother_no ='A'
union all
select t.mother_no,t.child_no,t.bo_qty,lev+1
from #bom t join sel s
on t.mother_no=s.child_no
)
select *,case when lev=1 then 'N' else 'Y' end as issub from sel