Query for Splitting a Name Field in SQL Server - sql-server

Question

I have a field [Name] which I need to break up into separate parts in a query. The field is in the format:
LastName,FirstName PossibleMiddle
Sample values:Doe,John Andrew
Smith,Jane
Goal for output:
[LastName] [FirstName] [MiddleName]
---------------- ---------------- ----------------
Doe John Andrew
Smith Jane
Here is the code I've been able to work out until now:
SELECT
LEFT([Name], CHARINDEX(',', [Name]) - 1) AS [Last Name],
SUBSTRING([Name], CHARINDEX(',', [Name]) +1, LEN([Name])) AS [First and Middle Name],
SUBSTRING([Name], CHARINDEX(',', [Name]) +1, (CHARINDEX(' ', [Name])-1)) AS [First Name]
FROM t1
This code is not right for a couple of reasons:
1. It fails because the second SUBSTRING is not correctly formulated. It assumes that there will always be a space, but there will actually only be a space if there is a middle name.
2. I don't want [First and Middle Name] as one (but I think once the first issue is resolved the rest will fall into place).
I feel like I'm missing something obvious with this but it's been a long morning of trying, searching and no solution yet. Thanks in advance for taking the time to look and respond.

Answer 1

using cross apply() so we do not have to repeat a function all over the place for the second part:
select
lastname = left(t.str,charindex(',',t.str)-1)
, firstname = left(x.val,charindex(' ',x.val+' '))
, middlename = nullif(right(x.val,len(x.val)-charindex(' ',x.val)),x.val)
from t
cross apply (
select val = stuff(t.str,1,charindex(',',t.str),'')
) x(val)
rextester demo: http://rextester.com/TUJNX20615
returns:
+----------+-----------+------------+
| lastname | firstname | middlename |
+----------+-----------+------------+
| Doe | John | Andrew |
| Smith | Jane | NULL |
+----------+-----------+------------+
To extend your example to include mononymous individuals:
create table t (str varchar(32))
insert into t values
('Doe,John Andrew')
,('Smith,Jane')
,('Sting') -- mononymous
select
lastname = left(t.str,charindex(',',t.str+',')-1)
, firstname = nullif(left(x.val,charindex(' ',x.val+' ')),t.str)
, middlename = nullif(right(x.val,len(x.val)-charindex(' ',x.val)),x.val)
from t
cross apply (
select val = stuff(t.str,1,charindex(',',t.str),'')
) x(val)
rextester demo: http://rextester.com/WPZXC58652
returns:
+----------+-----------+------------+
| lastname | firstname | middlename |
+----------+-----------+------------+
| Doe | John | Andrew |
| Smith | Jane | NULL |
| Sting | NULL | NULL |
+----------+-----------+------------+

Answer 2

I believe I have this working correctly. Basically, I used two case statements, based on whether or not there was a space in the name.
So, if there is a space in the name, then break on that for the first name. If not, take the rest of the field.
DECLARE #NAME VARCHAR(50)
SET #NAME = 'Smith,Jane' -- 'Smith,Jane Ann'
SELECT LEFT(#NAME, CHARINDEX(',', #NAME) - 1) AS LastName,
CASE
WHEN (CHARINDEX(' ', #NAME) = 0)
THEN SUBSTRING(#NAME, CHARINDEX(',', #NAME) + 1, 100)
ELSE
SUBSTRING(#NAME, CHARINDEX(',', #NAME) + 1, CHARINDEX(' ', #NAME) - CHARINDEX(',', #NAME))
END AS FirstName,
CASE
WHEN (CHARINDEX(' ', #NAME) = 0)
THEN ''
ELSE
SUBSTRING(#NAME, CHARINDEX(' ', #NAME) + 1, 100)
END AS MiddleName