I have not bought a textbook in over five years. Back then, O'Reilly was a reputable brand. So when I needed to learn PHP and MySQL, I bought this book without doing any research. I will never blindly buy an O'Reilly book again.
I got to page 11 before finding my first typo. After that, I lost track of all the typos and coding mistakes I've seen. Mind you, this is the 2nd edition of this book. Clearly, the authors did not proofread their book, nor did anyone else at O'Reilly, nor did anyone who read the 1st edition (?). I have learned to not trust anything in this book and instead use google for my php/mysql questions. Also, the mistakes are not all obvious typos -- some are mistakes in reasoning, which I can catch because I have extensive experience with computers.