I am trying to insert, update and display items that a user have collected. I heard that, using hash table would be more efficient, is it true? What is hash table? How to do it? I am using php5 and mysql. Any tutorial with simple code would be great.
hash table as such doesnt exist in php. Its got another name=>associative arrays. Have a look at the arrays manual http://in2.php.net/manual/en/book.array.php for more details.
Its basically like this. In an array you will have