I need help on how to parse JSON data in MySQL.
I can parse a column named config containing data such as:
{\"encounterId\":\"f45bf821-98e1-4496-82ef
It appears you are using https://common-schema.googlecode.com/svn/trunk/common_schema/doc/html/get_option.html. It specifies that subdictionaries are not supported, which I think is your problem here.
Mysql is not a great tool for parsing JSON.
I think there are some efforts for future versions like 5.7 to start including some support for JSON (see http://blog.ulf-wendel.de/2014/mysql-5-7-http-plugin-mysql/).
If you are on an earlier version now you might try using UDFs like http://www.slideshare.net/mobile/SvetaSmirnova/mysql-json-functions
HTH