Split string by space

This should work:

DECLARE @table TABLE (string VARCHAR(20))
INSERT @table VALUES ('ABC DEF')
INSERT @table VALUES ('XYZ')
INSERT @table VALUES ('EGF HIJ')

SELECT * FROM @table
WHERE CHARINDEX(' ', string) = 0

To get only 'XYZ' in the with a column containing

tableName.fieldName
'ABC DEF'
'XYZ'
'EGF HIJ' 

Do this

SELECT * 
FROM tableName
WHERE CHARINDEX(' ',fieldname) = 0

This is also work

select SUBSTRING(EmpName,0,CHARINDEX(' ',EmpName)),SUBSTRING(EmpName,CHARINDEX(' ',EmpName),LEN(EMPNAME)) 
from tblemployee