Using Unsafe Functions with JET Database Engine
March 21st, 2008I recently developed an HTA Application written in Javascript that used ADO to retrieve and update data in an MS Access database.
One of the calls tried to open a stored query but failed with the error ‘Unkown function’. It turns out that the query contained the Nz VBA function to convert null values into some other, zero in my case.
This works fine when run from within MS Access but when called externally would fail due to the JET 4.0 database engines sandbox mode.
I could have changed the registry key to allow the function but that would only work on my computer so as a fix I replaced all the references to Nz with IIf statements, not an elegant solution but it works none the less.