Description:
------------
I was doing an update with the method: $dbh->query($update).

I was getting the error. SQLSTATE[HY093]: Invalid parameter number: mixed name and positional parameters.

The problem was that my value string inside the query had a single semi-colon. And was causing this error. If i made it a double semi-colon it worked right.

Reproduce code:
---------------
The main code was a update statement for mysql:
UPDATE session SET user_id = '1', session = '$val' WHERE session_key = '$session_key'

The $val == 'started|i:1;i;user_id....'

Expected result:
----------------
I don't expect that the semi-colon inside the val code would through this error.