Write SQL query to solve given problem: What is the official full name of the current legislator whose current official Facebook presence is "senjoniernst"?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT T1.official_full_name FROM current AS T1 INNER JOIN `social-media` AS T2 ON T1.bioguide_id = T2.bioguide WHERE T2.facebook = 'senjoniernst'