Separate comma values into individual values - sql-server

Question

I need to separate columns in SQL Server
Table: columnsseparates
CREATE TABLE [dbo].[columnsseparates](
[id] [varchar](50) NULL,
[name] [varchar](500) NULL
)
INSERT [dbo].[columnsseparates] ([id], [name]) VALUES (N'1,2,3,4', N'abc,xyz,mn')
GO
INSERT [dbo].[columnsseparates] ([id], [name]) VALUES (N'4,5,6', N'xy,yz')
GO
INSERT [dbo].[columnsseparates] ([id], [name]) VALUES (N'7,100', N'yy')
INSERT [dbo].[columnsseparates] ([id], [name]) VALUES (N'101', N'oo,yy')
GO
based on above data I want output like below:
id | Name
1 |abc
2 |xyz
3 |mn
4 |null
4 |xy
5 |yz
6 |null
7 |yy
100 |null
101 |oo
null |yy
How to achieve this task in SQL Server?

Answer 1

Storing non-atomic values in column is a sign that schema should be normalised.
Naive approach using PARSENAME(up to 4 comma separated values):
SELECT DISTINCT s.id, s.name
FROM [dbo].[columnsseparates]
CROSS APPLY(SELECT REVERSE(REPLACE(id,',','.')) id,REVERSE(REPLACE(name, ',','.')) name) sub
CROSS APPLY(VALUES (REVERSE(PARSENAME(sub.id,1)), REVERSE(PARSENAME(sub.name,1))),
(REVERSE(PARSENAME(sub.id,2)), REVERSE(PARSENAME(sub.name,2))),
(REVERSE(PARSENAME(sub.id,3)), REVERSE(PARSENAME(sub.name,3))),
(REVERSE(PARSENAME(sub.id,4)), REVERSE(PARSENAME(sub.name,4)))
) AS s(id, name)
ORDER BY s.id;
db<>fiddle demo
Output:
+------+------+
| id | name |
+------+------+
| | |
| | yy |
| 1 | abc |
| 100 | |
| 101 | oo |
| 2 | xyz |
| 3 | mn |
| 4 | |
| 4 | xy |
| 5 | yz |
| 6 | |
| 7 | yy |
+------+------+

Answer 2

If you have more than 4 values, then you'll to use a string splitter that can return the ordinal value. I use delimitedsplit8k_LEAD here:
WITH Ids AS(
SELECT cs.id,
cs.name,
DS.ItemNumber,
DS.Item
FROM dbo.columnsseparates cs
CROSS APPLY dbo.DelimitedSplit8K_LEAD (cs.id,',') DS),
Names AS (
SELECT cs.id,
cs.name,
DS.ItemNumber,
DS.Item
FROM dbo.columnsseparates cs
CROSS APPLY dbo.DelimitedSplit8K_LEAD (cs.[name],',') DS)
SELECT I.Item AS ID,
N.Item AS [Name]
FROM Ids I
FULL OUTER JOIN Names N ON I.id = N.id
AND I.ItemNumber = N.ItemNumber
ORDER BY CASE WHEN I.Item IS NULL THEN 1 ELSE 0 END,
TRY_CONVERT(int,I.Item);