component plug-in

Hi,

i am exploring building the component plug-in for the below activities:

1. i will pass the parameter to the plug-in and based on that parameter the plug-in should get the data from the database and show it on the plug-in itself

2. if i modify the data on the plug-in it should update the same data on the database.

Please suggest the approach for the above requirement. please let me know if any sample plug-ins