What is the official full name of the current legislator whose current official Facebook presence is "senjoniernst"?
current official Facebook presence is "senjoniernst" refers to facebook = 'senjoniernst';
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'