MYSQL UPDATE SET on the Same Column but with multiple WHERE Clauses

Question

With MYSQL I'm using this query:

UPDATE CustomerDetails_COPY
SET Category_ID = 10
WHERE Category_ID = 2

Thats fine but I'd like to ad 15+ more SET/WHERE to it like:

UPDATE CustomerDetails_COPY
SET Category_ID = 9  WHERE Category_ID = 3
SET Category_ID = 12 WHERE Category_ID = 4
SET Category_ID = 11 WHERE Category_ID = 5
.....

How would I add to this?

EDIT:

As Per Hunters Suggestion:

UPDATE CustomerDetails_COPY
    SET Category_ID = CASE Category_ID
        WHEN 2 THEN 10 
        WHEN 3 THEN 9
        WHEN 4 THEN 12
        WHEN 5 THEN 11
    END
WHERE Category_ID IN (2,3,4,5)

This works Great! Thanks

Answer 1

Something like this should work for you:

UPDATE CustomerDetails_COPY
    SET Category_ID = CASE Category_ID
        WHEN 2 THEN 10 
        WHEN 3 THEN 9
        WHEN 4 THEN 12
        WHEN 5 THEN 11
    END
WHERE Category_ID IN (2,3,4,5)

Alternatively, as Simon suggested, you could do this to save from entering the values twice:

UPDATE CustomerDetails_COPY
    SET Category_ID = CASE Category_ID
        WHEN 2 THEN 10 
        WHEN 3 THEN 9
        WHEN 4 THEN 12
        WHEN 5 THEN 11
        ELSE Category_ID
    END

Source: http://www.karlrixon.co.uk/writing/update-multiple-rows-with-different-values-and-a-single-sql-query/