order by desc - with zeros on top

hiho

IIRC there where recently a sql code snippet, that solved the problem of
"ordering a list of ints descending - but keep the zero on top":

e.g.:

shown_production_id
---------------------
0
0
20270
20258
901
900

if there is no easy way or may memory plays tricks on me: dont bother
with this! i can solve it easily in the app - but why put work where the
dbs can already fix it.

--
cu