Question

I have table ‘posters’, table ‘reviews’ and table ‘trailers’. Every table is connected with an movieID column, but each table can be empty for certain movieIDs:

 ++ posters_table +++      ++ reviews_table ++      ++ trailers_table ++

--itemID--+--filename-    --itemID--+--review--    --itemID--+--trailer
----------------------    ---------------------    ---------------------
----001---+--0012343--    ----004---+--blalba--    ----002---+--002345--
----001---+--0013331--    ----004---+--xlalxa--    ----005---+--005434--
----002---+--0020052--    ----005---+--zlalza--    ----001---+--005335--

I want to COUNT() the number of posters, reviews and trailers for the specified movieID and get 0 if no available.

So if I want to count movieID = 001 I get: [‘posters’] = 2 / [‘reviews’] = 0 and [‘trailers’] = 1 (for example)

Can someone post the SQL query to do this?

Answer 1

select
    (select count(*) from posters_table  where itemId = ?) as posters,
    (select count(*) from reviews_table  where itemId = ?) as reviews,
    (select count(*) from trailers_table where itemId = ?) as trailers;