If all you are worried about is sorting then, provided the rest of your SQL is properly formed then:
- ORDER BY datalength(workingmethods) DESC, JOINDATE DESC;
Should sort by the datalength() then the JOINDATE
What I didnt' see was the closing semicolon ";"
1) Please clarify if you are only attempting to sort on two field within the same table, or what it is that you are actually attempting to do
2) Please post the entire SQL. All too often the SQL string is malformed. Spacing, square brackets and puncutation, and order of clauses are all importaint and can result in the best case what you want to see, simply return nothing, or can delete entire databases in the case of an action query.