I need your guide in the way i structure my websites.
I usually create custom functions in a file called myfunctions and from there i use those functions in all the pages where necessary to avoid retyping.
E.g mycustom_insert ($where, $what)
This function is dynamic as i can change variables on what to insert.
But my question is, is this safe knowing that some one else can simply execute such function on a slight chance given.
Example running such mycustom_insert() in a query url may end up inserting something into my database.
Is it safe for such functions to be created or should i manually retype codes on every page i want a particular function to run?