So in a year or so mysql_query will be gone in the newer versions of PHP. That being said the ever-so-used mysql_query used on sites will stop working on those who update.
Will this also affect things like mysql_num_rows and other functions? I mean, what alternative to mysql_query is there? I know there is mysqli but how is it different to that of mysql?
Yes. The whole (original) mysql extension is going away, not just the
mysql_queryfunction. The list of functions involved can be seen at:http://php.net/manual/en/ref.mysql.php