This is really off-topic for this site, but let's have a go anyway.

You need to join the BookAuthor table with itself. I'm old-skool so I do joins in the WHERE clause, but there's probably a simpler way to do it using an explicit JOIN clause.

select a.book
from BookAuthor a, BookAuthor b
where a.author = 'Smith' and b.author = 'Jones'
and a.book = b.book;

[download]

Update: The JOIN syntax looks like this:

select a.book
from BookAuthor a
inner join BookAuthor b
on a.book = b.book
where a.author = 'Smith' and b.author = 'Jones';

[download]

You should be able to omit the "INNER", but I was testing on a rather old version of MySQL which didn't support the abbreviated syntax.

--
<http://dave.org.uk>

"The first rule of Perl club is you do not talk about Perl club."
-- Chip Salzenberg

In reply to Re: Many-to-many relationships in databases by davorg
in thread Many-to-many relationships in databases : SOLVED by CountZero

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