How to do FULL [OUTER] JOIN in MySQL (MariaDB)

full_join.sql

-- First method
SELECT * FROM t1
LEFT JOIN t2 ON t1.id = t2.id
UNION
SELECT * FROM t1
RIGHT JOIN t2 ON t1.id = t2.id

-- Second Method
-- The query above works for special cases where a FULL OUTER JOIN operation would not produce any duplicate rows. 
-- The query above depends on the UNION set operator to remove duplicate rows introduced by the query pattern. 
-- We can avoid introducing duplicate rows by using an anti-join pattern for the second query, 
-- and then use a UNION ALL set operator to combine the two sets. In the more general case, 
-- where a FULL OUTER JOIN would return duplicate rows, we can do this

  SELECT * FROM t1
  LEFT JOIN t2 ON t1.id = t2.id
  UNION ALL
  SELECT * FROM t1
  RIGHT JOIN t2 ON t1.id = t2.id
  WHERE t1.id IS NULL