On Wed, Apr 1, 2009 at 1:27 PM, PJ <af.gour...@videotron.ca> wrote: > I am trying to select all books whose authors last names begin with I, J > or K. I have 3 tables: book, author and book_author. The following query > works with one condition but not with three. > SELECT * FROM book > WHERE id IN (SELECT bookID > FROM book_author WHERE authID IN (SELECT author.id > FROM author WHERE LEFT(last_name, 1 ) = 'I')); > > This does not work: > SELECT * FROM book > WHERE id IN (SELECT bookID > FROM book_author WHERE authID IN (SELECT author.id > FROM author WHERE LEFT(last_name, 1 ) = 'I' && LEFT(last_name, 1 > ) = 'J' && LEFT(last_name, 1 ) = 'K')) "; > > But this produces irrational results - there are no author names with > the last names starting with I, J or K. > SELECT * FROM book > WHERE id IN (SELECT bookID > FROM book_author WHERE authID IN (SELECT author.id > FROM author WHERE LEFT(last_name, 1 ) = '$Auth' & > LEFT(last_name, 1 ) = '$Auth1' & LEFT(last_name, 1 ) = '$Auth2')) "; > > I'm a little lost here. > Could somebody explain, please? > > Maybe the LIKE operator would be sufficient:
SELECT * from book WHERE last_name LIKE "I%" OR last_name LIKE "J%" OR last_name LIKE "K%"; David
