Select from two tables where one table's entry may be null

[bunner_bob]

I'm trying to select from two tables using something like the following:

"SELECT books.title, books.blurb, dates.start_date FROM books, dates WHERE books.book_id=" . $_GET['book_id'] . " AND books.book_id=dates.item_id AND dates.date_type='book'";

But if there's no date for a book, nothing gets selected.

How would I rephrase this so it will select the requested book even if there's no date assigned to that book?

[kpzani]

use a left join

"SELECT books.title, books.blurb, dates.start_date FROM books LEFT JOIN dates ON books.book_id=dates.item_id WHERE books.book_id=" . $_GET["book_id"] . " AND (dates.date_type='book' OR dates.date_type IS NULL)"

the last part is required as no matching records in dates will return NULL values in all columns from the dates table.