SQLite FULL JOIN

FULL JOIN отсутствует в SQLite.
Поэтому его можно и нужно заменить двумя LEFT JOIN

Пример из Вики:

SELECT employee.*, department.*
FROM   employee
       LEFT JOIN department
          ON employee.DepartmentID = department.DepartmentID
UNION ALL
SELECT employee.*, department.*
FROM   department
       LEFT JOIN employee
          ON employee.DepartmentID = department.DepartmentID
WHERE  employee.DepartmentID IS NULL