converting comma separated columns into multiple rows

create table Testdata(SomeID int, OtherID int, Data varchar(max))
insert Testdata select 1, 9, '18,20,22'
insert Testdata select 2, 8, '17,19'
insert Testdata select 3, 7, '13,19,20'
insert Testdata select 4, 6, ''

The query

SELECT A.OtherID,  
     Split.a.value('.', 'VARCHAR(100)') AS Data  
 FROM  
 (
     SELECT OtherID,  
         CAST ('<M>' + REPLACE(Data, ',', '</M><M>') + '</M>' AS XML) AS Data  
     FROM  Table1
 ) AS A CROSS APPLY Data.nodes ('/M') AS Split(a); 





Converting a single comma separated row into multiple rows






Ever since I wrote Converting multiple rows into a single comma separated row, I was trying to find a SQL command which will do the reverse, which is converting the single comma separated row back to multiple rows. I checked up a few blogs and I found out that it was possible to do with the help of custom functions or stored procedures, but I was not interested in all of them. Finally I got the answer that I was looking for, and now that I did, I did not waste precious time in noting it down here, lest I forget.

Let me try to show you what we are trying to achieve here with the help of an image



This can be done with the help of the below query
 SELECT A.[State],  
     Split.a.value('.', 'VARCHAR(100)') AS String  
 FROM  (SELECT [State],  
         CAST ('<M>' + REPLACE([City], ',', '</M><M>') + '</M>' AS XML) AS String  
     FROM  TableA) AS A CROSS APPLY String.nodes ('/M') AS Split(a);