mysql查询检索缺少一行

i have retrieve data from database with this query:

SELECT *
FROM news, necat
WHERE news.ns_cat = necat.nc_id 
ORDER BY ns_id DESC
LIMIT 0,4

and when this query run return only 3 row?! can you find any problem?

LIMIT limits the number of possible results, but if your query only returns 3 results, it cannot extend it :)