How can I use MySQL assign operator(:=) in hibernate native query?

Note that HHH-2697 is now fixed for Hibernate 4.1.3 You can now escape with backslash:

SELECT k.`news_master_id` AS id, @row \:= @row + 1 AS rownum 
    FROM keyword_news_list k 
    JOIN (SELECT @row \:= 0) r 
    WHERE k.`keyword_news_id` = :kid
ORDER BY k.`news_master_id` ASC

Another solution for those of us who can't make the jump to Hibernate 4.1.3.
Simply use /*'*/:=/*'*/ inside the query. Hibernate code treats everything between ' as a string (ignores it). MySQL on the other hand will ignore everything inside a blockquote and will evaluate the whole expression to an assignement operator.
I know it's quick and dirty, but it get's the job done without stored procedures, interceptors etc.

you can implement this is a slightly different way.. you need to replace the : operator with something else (say '|' char ) and in your interceptor replace the '|' with the : .

this way hibernate will not try to think the : is a param but will ignore it

For the interceptor logic you can refer to the hibernate manual

This has worked for me using MySQL 5.

remember, this replacing of : must be only done to ':=' and other MySQL specific requirments.. don't try to replace the : for the param-placeholders. (hibernate will not be able to identify the params then)