SELECT f.uniquename, ec.accession
  FROM dbxref ec
        JOIN feature_dbxref fdbx ON ec.dbxref_id=fdbx.dbxref_id
        JOIN feature f ON fdbx.feature_id=f.feature_id
        JOIN dbxref ON fdbx.dbxref_id=dbxref.dbxref_id
        JOIN db ON dbxref.db_id=db.db_id
 WHERE db.name = 'EC';