how to split a column into multiple value using sql - sql

Question

If I have thousands of rows with data and I would like to find out if the column called "Last
Name " contains both First Name and Last Name (could be middle initial too). What SQL command
do I use ? (SQL Server 2008). Once I find it, how do I split the Last Name field and place
first name or middle initial in their own columns ?
For example:
First Name MI Last Name
John B. Smith
Karen A. Jones
Jane Lawrence
Joan K. Bates
Could it be done in Excel as well ?

Answer 1

You could look for spaces in the last name:
select *
from t
where lastname like '% %';
You could look for rows where the first name is missing:
select *
from t
where firstname is null or firstname = '';
EDIT:
If we assume that the names are "simple" as given in the sample data, you can do:
update t
set firstname = left(lastname, charindex(' ', lastname) - 1),
lastname = right(lastname, charindex(' ', reverse(lastname))),
mi = (case when lastname like '% % %'
then rtrim(ltrim(substring(lastname, charindex(' ', lastname + 1), 2)))
end)
where lastname like '% %' and firstname is null;
This makes lots of assumptions about the formats . . . that there are no complete middle names, that there are no honorics, that there are no suffixes, that there are no multiple spaces together. But if your data is simple, it should work.
Here is an example of the logic in SQL Fiddle.

Answer 2

I would do it in two passes:
-- Set first name
UPDATE names
SET FirstName = SUBSTR(LastName,1,CHARINDEX(' ',LastName) - 1),
LastName = SUBSTR(LastName,CHARINDEX(' ',LastName) + 1, LEN(LastName))
WHERE FirstNAme IS NULL
AND CHARINDEX(' ',LastName) > 0
-- Set middle name
UPDATE names
SET MI = SUBSTR(LastName,1,CHARINDEX(' ',LastName) - 1),
LastName = SUBSTR(LastName,CHARINDEX(' ',LastName) + 1, LEN(LastName))
WHERE MI IS NULL
AND CHARINDEX(' ',LastName) > 0
You may have a few false positives but that should get the vast majority of cases.
I would STRONGLY recommend creating a transaction, doing the updates, doing a SELECT to see the results and rolling back the transaction since the update is not reversible.