openhab/openhab — pull request #1140 by jo-we (2014-06-11 12:54:10+00:00)
Title: MySQL: fix GroupItem handling

Mysql Persistence Service returns data of GroupItems (e.g. average Temperature) as StringType.
StringTypes are not supported in Charts.

with this fix the baseItem of GroupItems is used to detect the conversion method for the MySQL results.