The domain table provides a read-only mapping between domain names and the facebook-generated ids associated with them. Query this table to get domain ids for which to query domain metrics from the insights FQL table.
Highlighted rows are indexable / searchable and one is usually required in the WHERE portion of the query.
|domain_id||int||The domain id.|
|domain_name||string||The domain name.|
SELECT domain_id FROM domain WHERE domain_name='www.facebook.com'