Steps:

1: install Google Calendar Sync :
http://www.google.com/su...n/answer.py?answer=89955 

2:Link in GeniusConnect (GeniusConnect->Database->Assign Table) your Calendar folder to your SQL Database Table/View. (Don't forget to set Auto.Save and Delete options -Options Button on Assign Table )

3. Config sync scheduling (GeniusConnect->Synchronize Schedule)or sync with database using toolbar buttons

see also this great tool
https://caldavsynchronizer.org/