Попробуйте подстроку с CharIndex, чтобы найти пробел
with MyTable as
(
SELECT 'Bruno Miguel Alexandre' as FullName
UNION SELECT 'Miguel Bruno Alexandre'
UNION SELECT 'Bruno Alexandre'
UNION SELECT 'Bruno Miguel'
)
SELECT
SubString (FullName, 1, 1)
+ '.'
+ SubString (FullName, CHARINDEX (' ', FullName, 1), 8000)
FROM MyTable
Выходные данные
------------------------
B. Alexandre
B. Miguel
B. Miguel Alexandre
M. Bruno Alexandre
(4 row(s) affected)