How to split single cell into multiple columns in sql server 2008R2? - sql

Question

I want to split each name for individual columns
create table split_test(value integer,Allnames varchar(40))
insert into split_test values(1,'Vinoth,Kumar,Raja,Manoj,Jamal,Bala');
select * from split_test;
Value Allnames
-------------------
1 Vinoth,Kumar,Raja,Manoj,Jamal,Bala
Expected output
values N1 N2 N3 N4 N5 N6 N7.......N20
1 Vinoth Kumar Raja Manoj Jamal Bala

Answer 1

using this example you can get an idea.
declare #str varchar(max)
set #str = 'Hello world'
declare #separator varchar(max)
set #separator = ' '
declare #Splited table(id int identity(1,1), item varchar(max))
set #str = REPLACE(#str,#separator,'''),(''')
set #str = 'select * from (values('''+#str+''')) as V(A)'
insert into #Splited
exec(#str)
select * from #Splited

Answer 2

Here is an sql statement using recursive CTE to split names into rows, then pivot rows into columns.
SqlFiddle
with names as
(select
value,
1 as name_id,
substring(Allnames,1,charindex(',',Allnames+',', 0)-1) as name,
substring(Allnames,charindex(',',Allnames, 0)+1, 40) as left_names
from split_test
union all
select
value,
name_id +1,
case when charindex(',',left_names, 0)> 0 then
substring(left_names,1,charindex(',',left_names, 0)-1)
else left_names end as name,
case when charindex(',',left_names, 0)> 0 then
substring(left_names,charindex(',',left_names, 0)+1, 40)
else '' end as left_names
from names
where ltrim(left_names)<>'')
select value,
[1],[2],[3],[4],[5],[6],[7],[8],[9]
from (select value,name_id,name from names) as t1
PIVOT (MAX(name) FOR name_id IN ( [1],[2],[3],[4],[5],[6],[7],[8],[9] ) ) AS t2
UPDATE
#KM.'s answer might be a better way to split data into rows without recursive CTE table. It should be more efficient than this one. So I follow that example and simplified the part of null value process logic. Here is the result:
Step 1:
Create a table includes all numbers from 1 to a number grater than max length of Allnames column.
CREATE TABLE Numbers( Number int not null primary key);
with n as
(select 1 as num
union all
select num +1
from n
where num<100)
insert into numbers
select num from n;
Step 2:
Join data of split_test table with numbers table, we can get all the parts start from ,.
Then take the first part between 2 , form every row. If there are null values exists, add them with union.
select value ,
ltrim(rtrim(substring(allnames,number+1,charindex(',',substring(allnames,number,40),2)-2))) as name
from
(select value, ','+allnames+',' as allnames
from split_test) as t1
left join numbers
on number<= len(allnames)
where substring(allnames,number,1)=','
and substring(allnames,number,40)<>','
union
select value, Allnames
from split_test
where Allnames is null
Step 3: Pivot names from rows to columns like my first attempt above, omitted here.
SQLFiddle