sphinx and one-to-many associations

The examples I've seen for sphinx search don't really use joins. If I had a schema like this (one book has multiple reviews),

create table book ( id int auto_increment, title varchar(200), summary longtext );
create table reviews ( id int auto_increment, book_id int, review longtext );

What sort of query should I give to sphinx so that I can search for the words in the review and it will return the corresponding book. If I use a regular inner join each review will be a single document and that doesn't correspond to what's visible on the site (single page contains book info and all reviews).

What do you suggest? Should I create a denormalized table for the search documents and use the rendered page as input e.g.:

create table sphinx_input (开发者_运维技巧 
   id int, -- corresponds 1..1 to book.id
   contents longtext -- everything on the page
);

and modify this for every change to books and reviews?

You'll want to use GROUP_CONCAT, to collect all your data for reviews into the single result in Sphinx's sql_query. Perhaps something like the following:

SELECT books.id, books.title, books.summary,
  GROUP_CONCAT(reviews.review SEPARATOR ' ') AS reviews
FROM books LEFT OUTER JOIN reviews ON reviews.book_id = books.id
WHERE books.id >= $start AND books.id <= $end
GROUP BY books.id, books.title, books.summary

I'd recommend using an outer join so books without reviews are still returned as well.

you could just allow it to index reviews as usual and then perform the join from review ids to book ids in mysql after the results come back.