Parsing Name Field in SQL - sql

Question

I am trying to separate a name field into the appropriate fields. The name field is not consistently the same. It can show up as Doe III,John w or Doe,John, or Doe III,John, or Doe,John W or it may be lacking the suffix and or middle initial. Any ideas would be greatly appreciated.
SELECT (
CASE LEN(REPLACE(FirstName, ' ', ''))
WHEN LEN(FirstName + ' ') - 1
THEN PARSENAME(REPLACE(FirstName, ' ', '.'), 2)
ELSE PARSENAME(REPLACE(FirstName, ' ', '.'), 3)
END
) AS LastName
,(
CASE LEN(REPLACE(FirstName, ' ', ''))
WHEN LEN(FirstName + ',') - 1
THEN NULL
ELSE PARSENAME(REPLACE(FirstName, ' ', '.'), 2)
END
) AS Suffix
,PARSENAME(REPLACE(FirstName, ' ', '.'), 1) AS FirstName
FROM Trusts.dbo.tblMember
I need the name regardless of the format, as stated above, to parse into the appropriate fields of LastName,Suffix,FirstName,MiddleInitial, regardless of whether it has a suffix or a middle initial

Answer 1

If the given 4 names are the only type of cases, then you can use something like below.
Note: I used a CTE table tbl2 to separate comma_pos,first_space,second_space for better understanding in the main query. You can replace these value in main query with their corresponding function in CTE, to make the main query faster. I mean replace comma_pos in main query with charindex(',',name) an so on.
Also I am assuming that there are no leading/trailing or extra whitespaces or any junk character in name column. If you have, then sanitize your data first before proceeding.
Rexter Sample
with tbl2 as (
select tbl.*,
charindex(',',name) as comma_pos,
charindex(' ',name,1) first_space,
charindex(' ',name,charindex(' ',name,1)+1) second_space
from tbl)
select tbl2.name
,case when second_space <> 0
then substring(name,comma_pos+1,second_space-comma_pos-1)
when first_space > comma_pos
then substring(name,comma_pos+1,first_space-comma_pos-1)
else substring(name,comma_pos+1,len(name)-comma_pos)
end as first_name
,case when second_space <> 0
then substring(name,second_space+1,len(name)-second_space)
when first_space > comma_pos
then substring(name,first_space+1,len(name)-first_space)
end as middle_name
,case when first_space=0 or first_space>comma_pos
then substring(name,1,comma_pos-1)
else substring(name,1,first_space-1)
end as last_name
,case when first_space=0 or first_space>comma_pos
then null
else substring(name,first_space,comma_pos-first_space)
end as suffix
from tbl2;