What are the technical reasons for why one shouldn't use
mysql_* functions? (e.g.
Why should I use something else even if they work on my site?
If they don't work on my site, why do I get errors like
Warning: mysql_connect(): No such file or directory
The MySQL extension:
Since it is deprecated, using it makes your code less future proof.
Lack of support for prepared statements is particularly important as they provide a clearer, less error-prone method of escaping and quoting external data than manually escaping it with a separate function call.
See the comparison of SQL extensions.