Question

I have the below data

UniqueID    ID  data
1       1   a
2       1   2
3       1   b
4       1   1
5       2   d
6       2   3
7       2   r

The expected output being

ID  ConcatData
1   a,-,-,b,-
2   d,-,-,-,r

What we have to do is that, the number of numeric charecters has to be replaced with those many dashes(‘-‘) and then we need to merge the data for the respective id’s.

I am using the below query so far

declare @t table(UniqueID int identity(1,1), ID int, data varchar(10))  
insert into @t select 1, 'a' union all  select 1, '2' union all select 1, 'b' 
union all select 1, '1' union all select 2, 'd' union all select 2, '3' 
union all select 2, 'r' 

select * from @t

;with cte1 as 
(     
    select 
        UniqueId
        , id
        , data
        , case when isnumeric(data) = 1 then cast(data as int) end Level
         from @t     
    union all     
    select 
        UniqueId
        , id
        , CAST('-' as varchar(10))
        , Level - 1     
    from cte1     
    where Level > 0 ) 
,cte2 as
(
select id, GroupID = Dense_Rank() Over(Order by id),data, DataOrder = ROW_NUMBER() over(order by UniqueID, Level)
from cte1 
where Level is null or data = '-' 
) 

SELECT
ID
, (select data + ',' 
from cte2 t2 
where t2.GroupID = t1.GroupID
for XML path('')
) as ConcatData
from cte2 t1
group by t1.ID ,t1.GroupID

But the output is

ID  ConcatData
1   a,b,-,-,-,
2   d,r,-,-,-,

That is I am not able to position the dashes(‘-‘) in between the characters.

Please help

Answer 1

Try this:

;with cte1 as
(
select 
UniqueId
, id
, data
,case when isnumeric(data) = 1 
    THEN replicate(',-',data) 
    ELSE ',' + data end as string
from @t
)

select 
id
,LTRIM(STUFF(
    (
    SELECT
      ' ' + t2.String
    FROM Cte1 t2
    WHERE t2.id = t1.id
    FOR XML PATH('')
    ), 2, 1, ''
  )) As concatenated_string
from cte1 t1 group by t1.ID ,t1.ID 

Works for the sample data bove and might be a bit quicker than using cursors