Prepared queries don't work
Please make sure your variable name is all lower-case, and does not contain any symbols (including underscores (_) and hyphens (-)).
Furthermore, please make sure that you have a space character ( ) after your variable name, even if it's the end of your query (denoted by a ; - put a space ( ) before your ;).
If the data type you'd like to use in your prepared query is not supported by NetDB, please convert it to a string and try passing that in. Many data types will be parsed back to the desired type on the server.