官方說明不宜使用SQLite，說明有看沒有很懂就不亂解釋，但到蠻想試看看用的話會怎樣(哪來這麼多時間)，就是今天了。

在這之前已經成功地將PostgreSQL資料庫送上Heroku，這邊只是重新把settings.py的資料庫改為SQLite，然後執行'heroku run python3 manage.py migrate'，結果果然行不通：

File "/app/.heroku/python/lib/python3.7/site-packages/django/db/backends/base/base.py", line 217, in ensure_connection
    self.connect()
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/backends/base/base.py", line 195, in connect
    self.connection = self.get_new_connection(conn_params)
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/backends/sqlite3/base.py", line 194, in get_new_connection
    conn = Database.connect(**conn_params)
sqlite3.OperationalError: unable to open database file

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "manage.py", line 21, in <module>
    main()
  File "manage.py", line 17, in main
    execute_from_command_line(sys.argv)
  File "/app/.heroku/python/lib/python3.7/site-packages/django/core/management/__init__.py", line 381, in execute_from_command_line
    utility.execute()
  File "/app/.heroku/python/lib/python3.7/site-packages/django/core/management/__init__.py", line 375, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/app/.heroku/python/lib/python3.7/site-packages/django/core/management/base.py", line 323, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/app/.heroku/python/lib/python3.7/site-packages/django/core/management/base.py", line 364, in execute
    output = self.handle(*args, **options)
  File "/app/.heroku/python/lib/python3.7/site-packages/django/core/management/base.py", line 83, in wrapped
    res = handle_func(*args, **kwargs)
  File "/app/.heroku/python/lib/python3.7/site-packages/django/core/management/commands/migrate.py", line 87, in handle
    executor = MigrationExecutor(connection, self.migration_progress_callback)
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/migrations/executor.py", line 18, in __init__
    self.loader = MigrationLoader(self.connection)
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/migrations/loader.py", line 49, in __init__
    self.build_graph()
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/migrations/loader.py", line 212, in build_graph
    self.applied_migrations = recorder.applied_migrations()
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/migrations/recorder.py", line 73, in applied_migrations
    if self.has_table():
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/migrations/recorder.py", line 56, in has_table
    return self.Migration._meta.db_table in self.connection.introspection.table_names(self.connection.cursor())
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/backends/base/base.py", line 256, in cursor
    return self._cursor()
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/backends/base/base.py", line 233, in _cursor
    self.ensure_connection()
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/backends/base/base.py", line 217, in ensure_connection
    self.connect()
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/utils.py", line 89, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/backends/base/base.py", line 217, in ensure_connection
    self.connect()
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/backends/base/base.py", line 195, in connect
    self.connection = self.get_new_connection(conn_params)
  File "/app/.heroku/python/lib/python3.7/site-packages/django/db/backends/sqlite3/base.py", line 194, in get_new_connection
    conn = Database.connect(**conn_params)
django.db.utils.OperationalError: unable to open database file

這邊有出現兩個提示：
1.sqlite3.OperationalError: unable to open database file
2.django.db.utils.OperationalError: unable to open database file

後來想說如改把local資料庫送上去咧，先在網路上找到這個CLI指令'heroku db:push'，但又再看到另一篇，表示這個指令已不存在，被取代成'heroku pg:push'，而這邊的pg全名就是Postgres，內容也寫說Heroku至此不支援非Postgres資料庫了。