whats wrong with this php mysql_real_escape_string

Answer 1

Your problem here is not with mysql_real_escape_string. Your problem is with the fact that you don't have a connection to a server. Do you have a database 'periodic_table' running locally with 'username' and 'password' for your login credentials?

Answer 2

1. they used function name as a parameter for the another function.
2. Yes

Answer 3

I think mysql_real_escape_string needs a connection so it knows what charset is used.

also in php, single quotes are faster then double quotes as php doesn't have to process the contents of thr string looking for $varname etc.