Sql Select Everything After Character

DECLARE @x varchar(100)
SET @x = 'abcd-efgh-XXXX'
SELECT RIGHT(@x, CHARINDEX('-', REVERSE(@x)) - 1)

Using string split available from SQLServer 2016

;with cte
as
(
 select 
*,row_number() over (order by (select null)) as rownum
 from string_split('abcd-efgh-XXXX','-')
)
select top 1 * from cte 
order by rownum desc

@thegameiswar had a clever solution, since I needed the results from a comma delimited list. I don't have SQL 2016, so I made it work with a user defined split function.

;with cte
as
(
 select 
 *,row_number() over (order by (select null)) as rownum
 from database..[fn_SplitDelimitedList](@CommaDelimitedList,',')
)
select * from cte 
order by rownum desc

select substr('Prueba,Prueba2',instr('Prueba,Prueba2',',') + 1) from dual

SQL Server Management Studio v15.0.18206.0 (18.4):

RIGHT([col], CHARINDEX('-', REVERSE([col]), -1))