has the novel been adapted into any film?
Yes, in 2007.
Harry Potter and the Order of the Phoenix
In 2007, "Harry Potter and the Order of the Phoenix" was released in a film version directed by David Yates and written by Michael Goldenberg. 
when did the fifth harry potter come out 21 June 2003 who is the writer? J. K. Rowling what is the genre of this novel? Fantasy. what is the story about? It follows Harry Potter's struggles through his fifth year at Hogwarts School of Witchcraft and Wizardry, including the surreptitious return of the antagonist Lord Voldemort.
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Harry Potter and the Order of the Phoenix [SEP] Film
In 2007, "Harry Potter and the Order of the Phoenix" was released in a film version directed by David Yates and written by Michael Goldenberg. The film was produced by David Heyman's company, Heyday Films, alongside David Barron. The budget was reportedly between £75 and 100 million (US$150–200 million), and it became the unadjusted eleventh-highest-grossing film of all time and a critical and commercial success. The film opened to a worldwide 5-day opening of $333 million, the third best of all time, and grossed $940 million total, second to "" for the greatest total of 2007.