Transpose rows from split_string into columns - sql

Question

I'm stuck trying to transpose a set of rows into a table. In my stored procedure, I take a delimited string as input, and need to transpose it.
SELECT *
FROM string_split('123,4,1,0,0,5|324,2,0,0,0,4','|')
CROSS APPLY string_split(value,',')
From which I receive:
value value
123,4,1,0,0,5 123
123,4,1,0,0,5 4
123,4,1,0,0,5 1
123,4,1,0,0,5 0
123,4,1,0,0,5 0
123,4,1,0,0,5 5
324,2,0,0,0,4 324
324,2,0,0,0,4 2
324,2,0,0,0,4 0
324,2,0,0,0,4 0
324,2,0,0,0,4 0
324,2,0,0,0,4 4
The values delimited by | are client details. And within each client, there are six attributes, delimited by ,. I would like an output table of:
ClientId ClientTypeId AttrA AttrB AttrC AttrD
------------------------------------------------
123 4 0 0 0 5
324 2 0 0 0 4
What's the best way to go about this? I've been looking at PIVOT but can't make it work because it seems like I need row numbers, at least.

Answer 1

This answer assumes that row number function will "follow the order" of the string. If it does not you will need to write your own split that includes a row number in the resulting table. (This is asked on the official documentation page but there is no official answer given).
SELECT
MAX(CASE WHEN col = 1 THEN item ELSE null END) as ClientId,
MAX(CASE WHEN col = 2 THEN item ELSE null END) as ClientTypeId,
MAX(CASE WHEN col = 3 THEN item ELSE null END) as AttrA,
MAX(CASE WHEN col = 4 THEN item ELSE null END) as AttrB,
MAX(CASE WHEN col = 5 THEN item ELSE null END) as AttrC,
MAX(CASE WHEN col = 6 THEN item ELSE null END) as AttrD
FROM (
SELECT A.value as org, B.value as item,
ROW_NUMBER() OVER (partition by A.value) as col
FROM string_split('123,4,1,0,0,5|324,2,0,0,0,4','|') as A
CROSS APPLY string_split(A.value,',') as B
) X
GROUP BY org
You might get a message about nulls in aggregate function ignored. (I always forget which platforms care and which don't.) If you do you can replace the null with 0.
Note, this is not as fast and using a CTE to find the 5 commas in the string with CHARINDEX and then using SUBSTRING to extract the values. But I'm to lazy to write up that solution which I would need to test to get all the off by 1 issues right. Still, I suggest you do it that way if you have a big data set.

Answer 2

I know you already got it pretty much answered, but here you can find a PIVOT solution
select [ClientID],[ClientTypeId],[AttrA],[AttrB],[AttrC],[AttrD]
FROM
(
select case when ColumnRow = 1 then 'ClientID'
when ColumnRow = 2 then 'ClientTypeId'
when ColumnRow = 3 then 'AttrA'
when ColumnRow = 4 then 'AttrB'
when ColumnRow = 5 then 'AttrC'
when ColumnRow = 6 then 'AttrD' else null end as
ColumnRow,t.value,ColumnID from (
select ColumnID,z.value as stringsplit,b.value, cast(Row_number()
over(partition by z.value order by z.value) as
varchar(50)) as ColumnRow from (SELECT cast(Row_number() over(order by
a.value) as
varchar(50)) as ColumnID,
a.value
FROM string_split('123,4,1,0,0,5|324,2,0,0,0,4','|') a
)z
CROSS APPLY string_split(value,',') b
)t
) AS SOURCETABLE
PIVOT
(
MAX(value)
FOR ColumnRow IN ([ClientID],[ClientTypeId],[AttrA],[AttrB],[AttrC],
[AttrD])
)
AS
PivotTable