DECLARE SYNTAX

I am trying to convert a declare syntax from SQL to MySQL
the syntax is as follows:


declare [at] x int;
set [at] x = (SELECT max(ixBugEvent) FROM bugevent);

UPDATE bugevent
SET ixAttachment = (SELECT max(ixAttachment) FROM attachment),
ixBug = (SELECT max(ixBug) FROM bug)
WHERE ixBugEvent = [at] x;



but it is giving me an error. can anyone help.
thanks for your time in advance...