背景：
我是一開始沒有使用migrate這個功能，後來學到《Flask web開發》第八章後覺得不能遷移數據庫太不方便了，就想回來學習下flask-migrate的使用
問題：
但是這時候我的hello.py已經使用藍本分離成manage.py了，關於數據庫的信息位於models.py裏面，若是直接像書上一樣
先輸入python manage.py db init創建遷移倉庫，顯示的還正常：
Creating directory C:\Users\kai\PycharmProjects\practice\myflasky\migrations ... done
Creating directory C:\Users\kai\PycharmProjects\practice\myflasky\migrations\versions ... done
Generating C:\Users\kai\PycharmProjects\practice\myflasky\migrations\alembic.ini ... done
Generating C:\Users\kai\PycharmProjects\practice\myflasky\migrations\env.py ... done
Generating C:\Users\kai\PycharmProjects\practice\myflasky\migrations\README ... done
Generating C:\Users\kai\PycharmProjects\practice\myflasky\migrations\script.py.mako ... done
Please edit configuration/connection/logging settings in 'C:\\Users\\kai\\PycharmProjects\\practice\\myflasky\\migrations\\alembic.ini' before proceeding.但是之後再輸入python manage.py db upgrade創建遷移腳本後，就不對了：
(base) C:\Users\kai\PycharmProjects\practice\myflasky>python manage.py db migrate -m "initial migration"
INFO [alembic.runtime.migration] Context impl SQLiteImpl.
INFO [alembic.runtime.migration] Will assume non-transactional DDL.
INFO [alembic.env] No changes in schema detected.缺少
Detected added table 'roles'
Detected added table 'users'
這兩行，進入migrations文件夾中的versions發現的確是空的，證明創建腳本失敗
求解過程：
先是在網上查了一圈，參考了mrchi和杜志鵬的回答，瞭解到應該是flask-migrate沒有偵測到我的db數據導致的，但是我的manage.py中是有
from app import create_app, db
from app.models import User, Role
和
def make_shell_context():
return dict(app=current_app, db=db, User=User, Role=Role, Permission=Permission)
manager.add_command("shell", Shell(make_context=make_shell_context))
manager.add_command('db', MigrateCommand)借鑑杜志鵬的評論，嘗試cd到app中使用python models.py db migrate -m “initial migration”不過直接報錯了。
接着參考mrchi的問題中的描述，我在cmd中輸入命令前輸python manage.py shell進入交互，再輸入
from app import db
from app.models import User, Role來導入模型，在輸入創建腳本指令，不過結果還是一樣的。
期間我還在segment上提了問題，但是結果也還不是很滿意
最終解決辦法
在經歷前面的折騰，想到我的代碼和操作應該是沒有問題的，只可能是一些前提錯了，於是我就想到了
INFO [alembic.env] No changes in schema detected.這句話，既然說沒有變化你就不創建，那我就把你(sqlite)刪了，看你還說不說沒有變化，於是。。。
(base) C:\Users\kai\PycharmProjects\practice\myflasky>python manage.py db migrate -m "inital migration"
INFO [alembic.runtime.migration] Context impl SQLiteImpl.
INFO [alembic.runtime.migration] Will assume non-transactional DDL.
INFO [alembic.autogenerate.compare] Detected added table 'roles'
INFO [alembic.autogenerate.compare] Detected added index 'ix_roles_default' on '['default']'
INFO [alembic.autogenerate.compare] Detected added table 'users'
INFO [alembic.autogenerate.compare] Detected added index 'ix_users_email' on '['email']'
INFO [alembic.autogenerate.compare] Detected added index 'ix_users_username' on '['username']'
Generating C:\Users\kai\PycharmProjects\practice\myflasky\migrations\versions\c08a64ca29fc_inital_migration.py ... done
(base) C:\Users\kai\PycharmProjects\practice\myflasky>python manage.py db upgrade
INFO [alembic.runtime.migration] Context impl SQLiteImpl.
INFO [alembic.runtime.migration] Will assume non-transactional DDL.
INFO [alembic.runtime.migration] Running upgrade -> c08a64ca29fc, inital migration成功了！
不過頓時覺得自己像個逗比。。。
