That was, of course, it. I was so used to our "in-house" SQL with double quotes around strings that it never occurred to me that the outside world uses single quotes. Thanks, David!

Helped me today as well! Thanks, Robert.

@Vitaly Furman and @Alexander Koblov 
Hi Alexander and Vitaly,

Sorry for the delay in acknowledging your replies. This is still work in progress because it got superseded by other tasks. I'll let you know of the developments later.

Thanks,
Anna