[SQL] JOIN by mapping table

Code:TABLE: first_name
id
name

TABLE: last_name
id
name

TABLE: mapping
firstname_id
lastname_idHow can I map/match first_name.namewith last_name.name by mapping table?
I was trying to use INNER JOIN but that fails:

Code:SELECT first_name.name, last_name.name
FROM mapping
INNER JOIN first_name ON first_name.id = mapping.firstname_id
INNER JOIN last_name ON last_name.id = mapping.lastname_id;
ERROR: table name "mapping" specified more than once