Parsing a comma delimited column and transposing into rows [duplicate] - tsql

Question

This question already has answers here:
Turning a Comma Separated string into individual rows
(16 answers)
Closed 5 years ago.
Suppose I have a table like this with an undetermined number of comma-delimited values in one column:
thingID personID
1 123,234,345
2 456,567
and I want to get it into a form like this:
thingID personID
1 123
1 234
1 345
2 456
2 567
What is my best option for doing this?
Oh I should mention the data is in a SQL 2008 R2 database so I may not be able to use the very latest functionality.

Answer 1

Use CROSS APPLY with a string splitting function.
To find the string splitting function that works best for you, read Aaron Bertrand's Split strings the right way – or the next best way.
For this demonstration I've chosen to use the SplitStrings_XML function, simply because it's the first pure t-sql function in the article:
CREATE FUNCTION dbo.SplitStrings_XML
(
#List NVARCHAR(MAX),
#Delimiter NVARCHAR(255)
)
RETURNS TABLE
WITH SCHEMABINDING
AS
RETURN
(
SELECT Item = y.i.value('(./text())[1]', 'nvarchar(4000)')
FROM
(
SELECT x = CONVERT(XML, '<i>'
+ REPLACE(#List, #Delimiter, '</i><i>')
+ '</i>').query('.')
) AS a CROSS APPLY x.nodes('i') AS y(i)
);
GO
Now that we have a string splitting function, create and populate the sample table (Please save us this step in your future questions):
DECLARE #T AS TABLE
(
thingID int,
personID varchar(max)
)
INSERT INTO #T VALUES
(1, '123,234,345'),
(2, '456,567')
The query:
SELECT thingId, Item
FROM #T
CROSS APPLY dbo.SplitStrings_XML(personID, ',')
Results:
thingId Item
1 123
1 234
1 345
2 456
2 567
You can see a live demo on rextester.

Answer 2

There are several ways to do that. Here are two methods for SQL Server 2008:
XML-Method: requires the string to allow for the xml-trick (no invalid XML chars)
SELECT a.thingID, Split.a.value('.', 'VARCHAR(100)') AS Data
FROM (SELECT OtherID,
CAST('<M>' + REPLACE(personID, ',', '</M><M>') + '</M>' AS XML) AS Data
FROM table1) AS A CROSS APPLY Data.nodes ('/M') AS Split(a);
Recursive method:
;WITH tmp(thingID, DataItem, Data) AS (
SELECT thingID, LEFT(personID, CHARINDEX(',', personID + ',') - 1),
STUFF(personID, 1, CHARINDEX(',', personID + ','), '')
FROM table1
UNION ALL
SELECT thingID, LEFT(personID, CHARINDEX(',', personID + ',') - 1),
STUFF(personID, 1, CHARINDEX(',', personID + ','), '')
FROM tmp
WHERE Data > ''
)
SELECT thingID, DataItem AS personID
FROM tmp