Dynamic Update in infopath from Sharepoint List
Create a SP list with two columns Country and State.
Now in infopath create 2 fields Country and State as dropdown fields.
Create a data connection to receive from SP list which we created in step 1. Add the 2 fields from list in data connection wizard.
Select the Country dropdown box in infopath form and point the Country data to the list using the data source which we created in step 3.
Most important select the Check box
“Show only entries with unique display names”
Select the State dropdown box in infopath form and point the state data to the list using the data source which we created in step 3 and filter this data to the Country from list to the Country which we created in infopath form
Cascading update in infopath from SP list