How Do You Protect Your Database?

I have a webform on my site. It allows people to submit information to my database. At the moment, the webform has no protection.
What kind of security measures should I have in place to protect my database?
Are bad bots the only risk these days?
I use mysql_real_escape_string($_POST['']) to escape special characters, and I use trim($string) to trim whitespace from the beginning and end of every string. Should I be using any other PHP functions to protect my database?
Any…
How Do You Protect Your Database?

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