How to split names into first/middle/last if there are people who typed last/first/middle? Order known - sql

Question

I am trying to split names into first, middle, last, based on an indicated order. I am at a lost on how to do this, and any help would be much appreciated. I am using sql server 2008 for work.
I attached an example dataset and the ideal dataset I would like to create.
ID ORDER NAME
1 first, middle, last Bruce, Batman, Wayne
2 middle, last, first Superman, Kent, Clark
3 last, first, middle Prince, Diana, Wonderwoman
INTO:
ID ORDER NAME
1 first Bruce
1 middle Batman
1 last Wayne
2 middle Superman
2 last Kent
2 first Clark
3 last Prince
3 first Diana
3 middle Wonderwoman

Answer 1

SQL Server does not have very good string processing functions. You can do this using a recursive CTE, though:
with cte as (
select id,
convert(varchar(max), left(ord, charindex(',', ord) - 1)) as ord,
convert(varchar(max), left(name, charindex(',', name) - 1)) as name,
convert(varchar(max), stuff(ord, 1, charindex(',', ord) + 1, '')) as ord_rest,
convert(varchar(max), stuff(name, 1, charindex(',', name) + 1, '')) as name_rest,
1 as lev
from t
union all
select id,
convert(varchar(max), left(ord_rest, charindex(',', ord_rest + ',') - 1)) as ord,
convert(varchar(max), left(name_rest, charindex(',', name_rest + ',') - 1)) as name,
convert(varchar(max), stuff(ord_rest, 1, charindex(',', ord_rest + ',') + 1, '')) as ord_rest,
convert(varchar(max), stuff(name_rest, 1, charindex(',', name_rest + ',') + 1, '')) as name_rest,
lev + 1
from cte
where ord_rest <> '' and lev < 10
)
select id, ord, name
from cte
order by id, lev
Here is a db<>fiddle.

Answer 2

With the help of a parse/split function that returns the sequence, this becomes a small matter using a CROSS APPLY
Example
Select A.ID
,B.*
From YourTable A
Cross Apply (
Select [Order] = B1.RetVal
,[Name] = B2.RetVal
From [dbo].[tvf-Str-Parse]([ORDER],',') B1
Join [dbo].[tvf-Str-Parse]([NAME] ,',') B2 on B1.RetSeq=B2.RetSeq
) B
Returns
ID Order Name
1 first Bruce
1 middle Batman
1 last Wayne
2 middle Superman
2 last Kent
2 first Clark
3 last Prince
3 first Diana
3 middle Wonderwoman
The Function if Interested
CREATE FUNCTION [dbo].[tvf-Str-Parse] (#String varchar(max),#Delimiter varchar(10))
Returns Table
As
Return (
Select RetSeq = row_number() over (order by 1/0)
,RetVal = ltrim(rtrim(B.i.value('(./text())[1]', 'varchar(max)')))
From ( values (cast('<x>' + replace((Select replace(#String,#Delimiter,'§§Split§§') as [*] For XML Path('')),'§§Split§§','</x><x>')+'</x>' as xml).query('.'))) as A(x)
Cross Apply x.nodes('x') AS B(i)
);

Answer 3

I found the other answers a bit hard to follow - they're neat tricks for sure but I think anyone coming to maintain them might be like "whaaaat?". Here I work out the indexes of the commas (the first comma string index goes in o1/n1, the second comma goes in o2/n2) in the first cte, cut the string up (substring between 1 and first comma, substring between first and second comma, substring after third comma) in the second cte and then use a couple of unions to turn the results from 7 columns into 3
WITH idxs AS
(
SELECT
id,
order,
name,
CHARINDEX(',', [order]) as o1,
CHARINDEX(',', [order], CHARINDEX(',', [order]) + 1) as o2,
CHARINDEX(',', name) as n1,
CHARINDEX(',', name, CHARINDEX(',', name) + 1) as n2
FROM
t
),
cuts as (
SELECT
id,
SUBSTRING([order], 1, o1-1) as ord1,
SUBSTRING([order], o1+1, o2-o1-1) as ord2,
SUBSTRING([order], o2+1, 4000) as ord3,
SUBSTRING(name, 1, n1-1) as nam1,
SUBSTRING(name, n1+1, n2-n1-1) as nam2,
SUBSTRING(name, n2+1, 4000) as nam3
FROM
idxs
)
SELECT id, ord1 as [order], nam1 as name FROM cuts
UNION ALL
SELECT id, ord2, nam2 FROM cuts
UNION ALL
SELECT id, ord3, nam3 FROM cuts
Note that if your data sometimes has spaces in and sometimes does not you'll benefit from using either LTRIM/RTRIM in the output
if the spaces are always there after a comma, you could also adjust the substring indexes to cut the spaces out (any start index that is x+1 would be x+2 and the length would hence have to be -2)