Question

Possible Duplicate:
PDO Invalid parameter number – parameters in comments

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() [pdostatement.execute]: SQLSTATE[HY093]: Invalid parameter number: mixed named and positional parameters

The query I was using was similar to the following:

SELECT
    x
FROM
    y
WHERE
    -- CHECKING IF X = ? --
    x = :y
AND
    1 = 2

Obviously I had more parameters and a longer query.

Why does it give me this error?

Answer 1

The solution is obvious: PDO disregards comments as such and sees the ? as a positional parameter. Removing the ? in your comment solves this problem.

There’s a similar bug using unbound parameters in comments.