In a new post to his blog Till Klampaeckel looks at something the Zend Framework's Zend_Db component dosen't seem to support - an "IN" on a fetchAll - and how he worked around it.

The IN-clause is only supported when I wrap my statement with Zend_Db_Select, which is something I rarely do. Part of the reason is that I still don't feel comfortable writing my SQL in a DSL which doesn't really do anything besides wrapping a string into an object and IMHO it doesn't add to readability either. And the other reason is that I don't plan to run this import against any other database than MySQL. Which is why I don't see the need for abstraction either.

He shows some failing code where the IN isn't populated correctly when an array is passed in and the warnings that come with it. He solution's pretty simple, though - rewrite the query string before sending it with the correct number of bind locations ("?") for the number of parameters. In the comments, other approaches are suggested including using a simple select() call or tricking the bindings with a special kind of array.