在sqlserver中分隔单个列的值

Question

我在问题表中有一个名为categoryid的字段，其中可以输入多个值以显示不同的类别。 现在我想分开每个值并单独获取它。

值被分离，字符

例如

categoryid varchar 
3 
3,8 
5,9,7 
8,5,7,3,2 

我怎样才能分开它们中的每使用SQL查询？ 请帮忙

Answer 1

declare @T table 
(
    category_id varchar(10) 
) 

insert into @T 
select '3' union all 
select '3,8' union all 
select '5,9,7' union all 
select '8,5,7,3,2' 

;with C(ID, category_id) as 
(
    select cast(left(category_id, charindex(',', category_id+',', 1)-1) as int), 
     stuff(category_id, 1, charindex(',', category_id+',', 1), '') 
    from @T 
    union all 
    select cast(left(category_id, charindex(',', category_id+',', 1)-1) as int), 
     stuff(category_id, 1, charindex(',', category_id+',', 1), '') 
    from C 
    where len(category_id) > 0 
) 
select ID 
from C