Considering the name "Jonathan White" as example, here are a few tips for you:
Only first name
SELECT LEFT(Name, CHARINDEX(' ', Name) - 1)
First name plus initial of last name
SELECT LEFT(Name, CHARINDEX(' ', Name) + 1)
SELECT SUBSTRING(Name, 1, 1) + SUBSTRING(Name, CHARINDEX(' ', Name) + 1, 1)
There are some caveats with the above suggestions. They may not work as expected if:
- If there is only one name, e.g. "Peter"
- If there is more than 2 names, e.g. "Jennifer Alexandra Smith"
For more advanced processing a UDF (function) or SP (procedure) is probably better adviced.