T-SQL Substring - Last 3 Characters

Question

Using T-SQL, how would I go about getting the last 3 characters of a varchar column?

So the column text is IDS_ENUM_Change_262147_190

Answer 1

declare @newdata varchar(30)
set @newdata='IDS_ENUM_Change_262147_190'
select REVERSE(substring(reverse(@newdata),0,charindex('_',reverse(@newdata))))

=== Explanation ===

I found it easier to read written like this:

SELECT
    REVERSE( --4.
        SUBSTRING( -- 3.
            REVERSE(),
            0,
            CHARINDEX( -- 2.
                '',
                REVERSE() -- 1.
            )
        )
    )
FROM
    

1. Reverse the text
2. Look for the first occurrence of a specif char (i.e. first occurrence FROM END of text). Gets the index of this char
3. Looks at the reversed text again. searches from index 0 to index of your char. This gives the string you are looking for, but in reverse
4. Reversed the reversed string to give you your desired substring