PDO Invalid parameter number - parameters in comments

Question

Today I encountered a bug (in PDO) I never saw before, but is kinda obvious when you think about it.

I got the following error: Warning: PDOStatement::execute() [p

Answer 1

The solution is obvious: PDO disregards comments as such and tries to bind the non-existent variable ':Z'. You can't use parameters in comments in PDO (unless you do bind them).

There's a similar bug using question marks in comments.