Your json has syntactical errors.
You have {"resource":[{appUserCode:"101","apiKey";"202"}]}
It should be {"resource":[{"appUserCode":"101","apiKey";"202"}]}
I like to use this tool, http://jsonlint.com, to validate my json.
Let me also point you to the DreamFactory documentation on this subject, which is rather verbose. http://wiki.dreamfactory.com/DreamFactory/Features/Database/Records