UMMM... I think, no I'm almost absolutly sure it is illegal to obtain another sites database without some type of contract with written permission. Then they would give you access to what you needed, most likely. I hope I didn't misunderstand your post We just don't support hacking here.
I am making a books website but i have no database
How to managae this problem please tell me any solution.
I have just done a yahoo search to see if there were any databases online available for download and could not find a single one. So it appears that there are three ways of getting the data into your website they are:
So those are your options and if I were to choose one I would choose option 2 as you would then own full rights to the data and might even be able to resell it.
http://isbndb.com/ has an api you can use to access THEIR data. I can't see anybody giving away a database for free.
You've also got the problem of data veracity with many free sources. Some of the dbs (possibly isbndb.com included) seem to 'scrape' data from sites - some data on those sites may be unverified or just downright wrong.