Subscribed Web Alert

Will return you all the web alerts. The ID column represent the ID for the web alert

SELECT *
FROM subscriptions_tbl

Will return you the folder(s) where the web alert is assigned
The column Value_number represents the ID column from subscriptions_tbl
The column Object_ID represents the folder ID where the web alert is assigned

SELECT *
FROM dynamic_data_tbl
WHERE definition_id = 1
	AND definition_object_id = 1

Will return you the users subscribed to the web alert
The column Value_number represents the ID column from subscriptions_tbl
The column Object_ID represents the user ID for the user subscribed to the web alert

SELECT *
FROM dynamic_data_tbl
WHERE definition_id = 1
	AND definition_object_id = 2