makemigrations [Django] ERROR: You are trying to add a non-nullable field.TILmakemigrationsdjango [Django]導入中の移行エラーdeploypythonerrormakemigrationsdjangoMigrate
[Django] ERROR: You are trying to add a non-nullable field.TILmakemigrationsdjango [Django]導入中の移行エラーdeploypythonerrormakemigrationsdjangoMigrate