sql/mysql filter including only the max value

Question

I have a resultset that is like this:

ID | name  | myvalue
 1 | A1    | 22
 2 | A2    | 22
 3 | A3    | 21
 4 | A4    | 33
 5 | A5    | 33
 6 | A6    | 10
 7 | A7    | 10
 8 | A8    | 10
 9 | A9    | 5

what i want, is to include only rows that contains the highest "myvalue" available (in the previous example is 33), then:

ID | name  | myvalue
 4 | A4    | 33
 5 | A5    | 33

IE the query should pick the highest "myvalue" available (IE 33) and it should remove the rows that have myvalue < 33

SELECT ..... WHERE myvalue = THE_HIGHEST_OF(myvalue)

Hoping to have been clear...

thank you in advance

---

edit:

my current query is

SELECT 
    *,
    (very long code that returns a integer as relevance score) AS myvalue
FROM
    mytable
HAVING
    myvalue = ?????
ORDER BY
    myvalue DESC

now the highest myvalue can be 10, 20, 30, any number... in the final resultset i want to include only the rows that have the highest possible relevance score

ive tried using GROUP BY, but i always need to repeat the...

    (very long code that returns a integer as relevance score) AS myvalue

...twice

Answer 1

SELECT * FROM t WHERE myValue IN (SELECT max(myValue) From t);

###See this SQLFiddle

Edit:

As per discussion with OP. OP wants to use alias in WHERE clause. But you can only use column aliases in GROUP BY, ORDER BY, or HAVING clauses.
Look at this answer.