flask 擴充套件（一）
阿新 • • 發佈：2019-12-31
Flask-Script 擴充套件命令列
from flask import Flask
from flask_script import Manager
app = Flask(__name__)
manager = Manager(app)
@app.route('/')
def index():
return '我的快樂時代'
if __name__ == "__main__":
manager.run()
複製程式碼通過使用Flask-Script擴充套件，我們可以在Flask伺服器啟動的時候，通過命令列的方式傳入引數。而不僅僅通過app.run()方法中傳參，
比如我們可以通過python hello.py runserver --host ip地址，告訴伺服器在哪個網路介面監聽來自客戶端的連線。預設情況下，伺服器只監聽來自伺服器所在計算機發起的連線，即localhost連線。
我們可以通過 python hello.py runserver --help 來檢視引數:
Flask-WTF
相關參考連結
關於 web 表單
web表單是web應用程式的基本功能。 它是HTML頁面中負責資料採集的部件。表單有三個部分組成：表單標籤、表單域、表單按鈕。表單允許使用者輸入資料，負責HTML頁面資料採集，通過表單將使用者輸入的資料提交給伺服器。
在Flask中，為了處理web表單，我們一般使用Flask-WTF擴充套件，它封裝了WTForms，並且它有驗證表單資料的功能。
WTForms支援的HTML標準欄位
WTForms常用驗證函式
表單中的 CSRF
使用Flask-WTF需要配置引數SECRET_KEY。 CSRF_ENABLED是為了CSRF（跨站請求偽造）保護。 SECRET_KEY用來生成加密令牌，當CSRF啟用的時候，該設定會根據設定的密匙生成加密令牌。
在HTML頁面中直接寫form表單的模式
檔案結構：
templates/login.html:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Login</title>
</head>
<body>
<form method='post'>
<input type="text" name="username" placeholder='Username'>
<input type="password" name="password" placeholder='password'>
<input type="submit">
</form>
</body>
</html>
複製程式碼 hello.py
from flask import Flask,request,render_template
app = Flask(__name__)
@app.route('/login',methods=['GET','POST'])
def login():
if request.method == 'POST':
username = request.form['username']
password = request.form['password']
print(username,password)
return render_template('login.html',method=request.method)
if __name__ == "__main__":
app.run()
複製程式碼使用Flask-WTF實現表單
安裝：
pip install flask-wtf
複製程式碼首先需要配置引數： app.config['SECRET_KEY'] = 'ruiyang'
檔案結構：
hello.py
from flask import Flask,render_template,redirect,url_for,flash
from flask_wtf import Form
from wtforms import SubmitField,StringField,PasswordField
from wtforms.validators import DataRequired,EqualTo
app = Flask(__name__)
app.config['SECRET_KEY'] = 'ruiyang'
class Login(Form):
us = StringField(label=u'使用者：',validators=[DataRequired()])
ps = PasswordField(label=u'密碼',validators=[DataRequired(),EqualTo('ps2','err')])
ps2 = PasswordField(label=u'確認密碼',validators=[DataRequired()])
submit = SubmitField(u'提交')
@app.route('/','POST'])
def index():
form = Login()
if form.validate_on_submit():
name = form.us.data
pswd = form.ps.data
pswd2 = form.ps2.data
print(name,pswd,pswd2)
return "login seccess"
else:
if request.method == 'POST':
flash(u'資訊有誤，請重新輸入！')
print(form.validate_on_submit())
return render_template('login.html',form=form)
if __name__ == '__main__':
app.run(debug=True)
複製程式碼templates/login.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Login</title>
</head>
<body>
<form method="post">
{{ form.csrf_token() }}
{{ form.us.label }}
<p>{{ form.us }}</p>
{{ form.ps.label }}
<p>{{ form.ps }}</p>
{{ form.ps2.label }}
<p>{{ form.ps2 }}</p>
<p>{{ form.submit() }}</p>
{% for x in get_flashed_messages() %}
{{ x }}
{% endfor %}
</form>
</body>
</html>
複製程式碼flask-sqlalchemy
相關參考連結
安裝
pip install flask-sqlalchemy
複製程式碼需要連線mysql資料庫，仍然需要安裝 flask-mysqldb
pip install flask-mysqldb
複製程式碼配置
Flask的資料庫設定：
app.config['SQLALCHEMY_DATABASE_URI'] = 'mysql://root:[email protected]:3306/test'
複製程式碼常用的SQLAlchemy欄位型別
常用的SQLAlchemy列選項
常用的SQLAlchemy關係選項
在程式中的基礎操作
建立測試資料：
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
app = Flask(__name__)
# 設定連線資料庫的URL
app.config['SQLALCHEMY_DATABASE_URI'] = 'mysql://root:[email protected]:3306/test'
# 設定每次請求結束後會自動提交資料庫中的改動
app.config['SQLALCHEMY_COMMIT_ON_TEARDOWN'] = True
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = True
# 查詢時會顯示原始SQL語句
app.config['SQLALCHEMY_ECHO'] = True
db = SQLAlchemy(app)
class Role(db.Model):
__tablename__ = 'roles'
id = db.Column(db.Integer,primary_key=True)
name = db.Column(db.String(64),unique=True)
us = db.relationship('User',backref='role')
def __repr__(self):
return 'Role:{}'.format(self.name)
class User(db.Model):
__tablename__ = 'users'
id = db.Column(db.Integer,unique=True,index=True)
email = db.Column(db.String(64),unique=True)
pswd = db.Column(db.String(64))
role_id = db.Column(db.Integer,db.ForeignKey('roles.id'))
def __repr__(self):
return 'User:{}'.format(self.name)
if __name__ == '__main__':
db.drop_all()
db.create_all()
ro1 = Role(name='admin')
ro2 = Role(name='user')
db.session.add_all([ro1,ro2])
db.session.commit()
us1 = User(name='wang',email='[email protected]',pswd='123456',role_id=ro1.id)
us2 = User(name='zhang',email='[email protected]',pswd='201512',role_id=ro2.id)
us3 = User(name='chen',email='[email protected]',pswd='987654',role_id=ro2.id)
us4 = User(name='zhou',email='[email protected]',pswd='456789',role_id=ro1.id)
db.session.add_all([us1,us2,us3,us4])
db.session.commit()
app.run(debug=True)
複製程式碼執行程式之後啟動 flask shell 進行操作：
建立和刪除表：
>>> db.create_all()
2019-08-10 13:45:02,631 INFO sqlalchemy.engine.base.Engine DESCRIBE `roles`
2019-08-10 13:45:02,631 INFO sqlalchemy.engine.base.Engine ()
2019-08-10 13:45:02,632 INFO sqlalchemy.engine.base.Engine DESCRIBE `users`
2019-08-10 13:45:02,632 INFO sqlalchemy.engine.base.Engine ()
>>> db.drop_all()
2019-08-10 13:45:11,267 INFO sqlalchemy.engine.base.Engine DESCRIBE `roles`
2019-08-10 13:45:11,267 INFO sqlalchemy.engine.base.Engine ()
2019-08-10 13:45:11,268 INFO sqlalchemy.engine.base.Engine DESCRIBE `users`
2019-08-10 13:45:11,268 INFO sqlalchemy.engine.base.Engine ()
2019-08-10 13:45:11,270 INFO sqlalchemy.engine.base.Engine
DROP TABLE users
2019-08-10 13:45:11,270 INFO sqlalchemy.engine.base.Engine ()
2019-08-10 13:45:11,283 INFO sqlalchemy.engine.base.Engine COMMIT
2019-08-10 13:45:11,284 INFO sqlalchemy.engine.base.Engine
DROP TABLE roles
2019-08-10 13:45:11,284 INFO sqlalchemy.engine.base.Engine ()
2019-08-10 13:45:11,294 INFO sqlalchemy.engine.base.Engine COMMIT
複製程式碼插入單條資料：
>>> from hello import Role
>>> role_admin = Role(name="admin")
>>> db.session.add(role_admin)
>>> db.session.commit()
2019-08-10 13:46:40,071 INFO sqlalchemy.engine.base.Engine BEGIN (implicit)
2019-08-10 13:46:40,071 INFO sqlalchemy.engine.base.Engine INSERT INTO roles (name) VALUES (%s)
2019-08-10 13:46:40,072 INFO sqlalchemy.engine.base.Engine ('admin',)
2019-08-10 13:46:40,073 INFO sqlalchemy.engine.base.Engine COMMIT
>>> role1 = Role(name="user1")
>>> db.session.add(role1)
>>> db.session.commit()
2019-08-10 13:47:03,975 INFO sqlalchemy.engine.base.Engine BEGIN (implicit)
2019-08-10 13:47:03,975 INFO sqlalchemy.engine.base.Engine INSERT INTO roles (name) VALUES (%s)
2019-08-10 13:47:03,975 INFO sqlalchemy.engine.base.Engine ('user1',)
2019-08-10 13:47:03,976 INFO sqlalchemy.engine.base.Engine COMMIT
>>> role2 = Role(name="ruiyang")
>>> db.session.add(role2)
>>> db.session.commit()
2019-08-10 13:47:39,205 INFO sqlalchemy.engine.base.Engine BEGIN (implicit)
2019-08-10 13:47:39,205 INFO sqlalchemy.engine.base.Engine INSERT INTO roles (name) VALUES (%s)
2019-08-10 13:47:39,205 INFO sqlalchemy.engine.base.Engine ('ruiyang',)
2019-08-10 13:47:39,206 INFO sqlalchemy.engine.base.Engine COMMIT
複製程式碼插入多條資料： add_all()
>>> us1 = User(name='wang',role_id=role_admin.id)
2019-08-10 13:49:09,064 INFO sqlalchemy.engine.base.Engine BEGIN (implicit)
2019-08-10 13:49:09,064 INFO sqlalchemy.engine.base.Engine SELECT roles.id AS roles_id,roles.name AS roles_name
FROM roles
WHERE roles.id = %s
2019-08-10 13:49:09,065 INFO sqlalchemy.engine.base.Engine (1,)
>>> us2 = User(name='zhang',role_id=role1.id)
2019-08-10 13:49:52,577 INFO sqlalchemy.engine.base.Engine SELECT roles.id AS roles_id,roles.name AS roles_name
FROM roles
WHERE roles.id = %s
2019-08-10 13:49:52,577 INFO sqlalchemy.engine.base.Engine (2,)
>>> us3 = User(name='chen',role_id=role1.id)
>>> us4 = User(name='zhou',role_id=role2.id)
2019-08-10 13:50:20,853 INFO sqlalchemy.engine.base.Engine SELECT roles.id AS roles_id,roles.name AS roles_name
FROM roles
WHERE roles.id = %s
2019-08-10 13:50:20,853 INFO sqlalchemy.engine.base.Engine (3,)
>>> db.session.add_all([us1,us4])
>>> db.session.commit()
2019-08-10 13:50:38,442 INFO sqlalchemy.engine.base.Engine INSERT INTO users (name,email,role_id) VALUES (%s,%s,%s)
2019-08-10 13:50:38,442 INFO sqlalchemy.engine.base.Engine ('wang','[email protected]','123456',1)
2019-08-10 13:50:38,444 INFO sqlalchemy.engine.base.Engine INSERT INTO users (name,444 INFO sqlalchemy.engine.base.Engine ('zhang','[email protected]','201512',2)
2019-08-10 13:50:38,445 INFO sqlalchemy.engine.base.Engine INSERT INTO users (name,445 INFO sqlalchemy.engine.base.Engine ('chen','[email protected]','987654',446 INFO sqlalchemy.engine.base.Engine INSERT INTO users (name,446 INFO sqlalchemy.engine.base.Engine ('zhou','[email protected]','456789',3)
2019-08-10 13:50:38,446 INFO sqlalchemy.engine.base.Engine COMMIT
複製程式碼使用 filter_by 精確查詢: 查詢第一個和全部
>>> User.query.filter_by(name='wang').first()
2019-08-10 13:54:08,112 INFO sqlalchemy.engine.base.Engine SELECT users.id AS users_id,users.name AS users_name,users.email AS users_email,users.pswd AS users_pswd,users.role_id AS users_role_id
FROM users
WHERE users.name = %s
LIMIT %s
2019-08-10 13:54:08,113 INFO sqlalchemy.engine.base.Engine ('wang',1)
User:wang
>>> User.query.filter_by(name='wang').all()
2019-08-10 13:54:15,698 INFO sqlalchemy.engine.base.Engine SELECT users.id AS users_id,users.role_id AS users_role_id
FROM users
WHERE users.name = %s
2019-08-10 13:54:15,698 INFO sqlalchemy.engine.base.Engine ('wang',)
[User:wang]
複製程式碼使用 filter 模糊查詢，返回結尾字元為 g 的所有資料：
>>> User.query.filter(User.name.endswith('g')).all()
2019-08-12 09:01:24,998 INFO sqlalchemy.engine.base.Engine SELECT users.id AS users_id,users.role_id AS users_role_id
FROM users
WHERE (users.name LIKE concat('%%',%s))
2019-08-12 09:01:24,999 INFO sqlalchemy.engine.base.Engine ('g',)
[User:wang,User:zhang]
複製程式碼邏輯非：返回名字不等於 wang 的全部資料：
>>> User.query.filter(User.name!='wang').all()
2019-08-12 09:02:03,321 INFO sqlalchemy.engine.base.Engine SELECT users.id AS users_id,users.role_id AS users_role_id
FROM users
WHERE users.name != %s
2019-08-12 09:02:03,321 INFO sqlalchemy.engine.base.Engine ('wang',)
[User:zhang,User:chen,User:zhou]
複製程式碼邏輯與，需要匯入 _and 返回and() 條件滿足的所有資料：
>>> User.query.filter(and_(User.name != 'wang',User.email.endswith('163.com'))).all()
2019-08-12 09:22:21,840 INFO sqlalchemy.engine.base.Engine SELECT users.id AS users_id,users.role_id AS users_role_id
FROM users
WHERE users.name != %s AND (users.email LIKE concat('%%',%s))
2019-08-12 09:22:21,841 INFO sqlalchemy.engine.base.Engine ('wang','163.com')
[User:zhou]
複製程式碼邏輯或，需要匯入 or_
>>> from sqlalchemy import or_
>>> User.query.filter(or_(User.name != "wang",User.email.endswith('163.com'))).all()
2019-08-12 09:24:17,577 INFO sqlalchemy.engine.base.Engine SELECT users.id AS users_id,users.role_id AS users_role_id
FROM users
WHERE users.name != %s OR (users.email LIKE concat('%%',%s))
2019-08-12 09:24:17,577 INFO sqlalchemy.engine.base.Engine ('wang','163.com')
[User:wang,User:zhang,User:zhou]
複製程式碼not_ 相當於取反
>>> from sqlalchemy import not_
>>> User.query.filter(not_(User.name == "chen")).all()
2019-08-12 09:25:49,716 INFO sqlalchemy.engine.base.Engine SELECT users.id AS users_id,users.role_id AS users_role_id
FROM users
WHERE users.name != %s
2019-08-12 09:25:49,716 INFO sqlalchemy.engine.base.Engine ('chen',User:zhou]
複製程式碼查詢資料後刪除
>>> user = User.query.first()
2019-08-12 09:26:58,334 INFO sqlalchemy.engine.base.Engine SELECT users.id AS users_id,users.role_id AS users_role_id
FROM users
LIMIT %s
2019-08-12 09:26:58,334 INFO sqlalchemy.engine.base.Engine (1,)
>>> user
User:wang
>>> db.session.delete(user)
>>> db.session.commit()
2019-08-12 09:27:27,209 INFO sqlalchemy.engine.base.Engine DELETE FROM users WHERE users.id = %s
2019-08-12 09:27:27,209 INFO sqlalchemy.engine.base.Engine (1,)
2019-08-12 09:27:27,225 INFO sqlalchemy.engine.base.Engine COMMIT
>>> User.query.all()
2019-08-12 09:27:36,097 INFO sqlalchemy.engine.base.Engine BEGIN (implicit)
2019-08-12 09:27:36,098 INFO sqlalchemy.engine.base.Engine SELECT users.id AS users_id,users.role_id AS users_role_id
FROM users
2019-08-12 09:27:36,098 INFO sqlalchemy.engine.base.Engine ()
[User:zhang,User:zhou]
複製程式碼更新資料：
>>> user = User.query.first()
2019-08-12 09:28:09,206 INFO sqlalchemy.engine.base.Engine SELECT users.id AS users_id,users.role_id AS users_role_id
FROM users
LIMIT %s
2019-08-12 09:28:09,206 INFO sqlalchemy.engine.base.Engine (1,)
>>> user
User:zhang
>>> user.name
'zhang'
>>> user.name = "furuiyang"
>>> db.session.commit()
2019-08-12 09:28:34,955 INFO sqlalchemy.engine.base.Engine UPDATE users SET name=%s WHERE users.id = %s
2019-08-12 09:28:34,955 INFO sqlalchemy.engine.base.Engine ('furuiyang',2)
2019-08-12 09:28:34,960 INFO sqlalchemy.engine.base.Engine COMMIT
>>> User.query.first()
2019-08-12 09:28:46,551 INFO sqlalchemy.engine.base.Engine BEGIN (implicit)
2019-08-12 09:28:46,552 INFO sqlalchemy.engine.base.Engine SELECT users.id AS users_id,users.role_id AS users_role_id
FROM users
LIMIT %s
複製程式碼2019-08-12 09:28:46,552 INFO sqlalchemy.engine.base.Engine (1,) User:furuiyang
使用 update 更新資料：
>>> User.query.filter_by(name='furuiyang').update({"name": "Katrina"})
2019-08-12 09:30:38,053 INFO sqlalchemy.engine.base.Engine SELECT users.id AS users_id,users.role_id AS users_role_id
FROM users
WHERE users.id = %s
2019-08-12 09:30:38,054 INFO sqlalchemy.engine.base.Engine (3,)
2019-08-12 09:30:38,058 INFO sqlalchemy.engine.base.Engine SELECT users.id AS users_id,059 INFO sqlalchemy.engine.base.Engine (4,060 INFO sqlalchemy.engine.base.Engine UPDATE users SET name=%s WHERE users.name = %s
2019-08-12 09:30:38,060 INFO sqlalchemy.engine.base.Engine ('Katrina','furuiyang')
1
>>> User.query.all()
2019-08-12 09:31:00,951 INFO sqlalchemy.engine.base.Engine SELECT users.id AS users_id,users.role_id AS users_role_id
FROM users
2019-08-12 09:31:00,951 INFO sqlalchemy.engine.base.Engine ()
[User:Katrina,User:zhou]
複製程式碼關聯查詢示例： 角色和使用者是一對多的關係。一個角色可以有多個使用者，但是一個使用者只能屬於一個角色：
查詢某個角色組（ruiyang） 下的全部使用者：
>>> role_ruiyang = Role.query.filter_by(name='ruiyang').first()
2019-08-12 09:35:24,302 INFO sqlalchemy.engine.base.Engine SELECT roles.id AS roles_id,roles.name AS roles_name
FROM roles
WHERE roles.name = %s
LIMIT %s
2019-08-12 09:35:24,302 INFO sqlalchemy.engine.base.Engine ('ruiyang',1)
>>> role_ruiyang
Role:ruiyang
>>> role_ruiyang.us
2019-08-12 09:35:41,776 INFO sqlalchemy.engine.base.Engine SELECT users.id AS users_id,users.role_id AS users_role_id
FROM users
WHERE %s = users.role_id
2019-08-12 09:35:41,776 INFO sqlalchemy.engine.base.Engine (3,)
[User:zhou]
複製程式碼查詢某個使用者所屬的角色：
>>> user = User.query.get(3)
>>> user
User:chen
>>> user.role
Role:user1
複製程式碼資料庫遷移之 Flask-Migrate
安裝
pip install flask-migrate
複製程式碼建立一個測試 app
如下：定義了兩個模型類，作者和書名：
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'mysql://root:[email protected]:3306/test'
app.config['SQLALCHEMY_COMMIT_ON_TEARDOWN'] = True
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
db = SQLAlchemy(app)
class Author(db.Model):
"""
定義模型類-作者
"""
__tablename__ = 'author'
id = db.Column(db.Integer,primary_key=True)
name = db.Column(db.String(32),unique=True)
email = db.Column(db.String(64))
au_book = db.relationship('Book',backref='author')
def __str__(self):
return f'Author:{self.name}'
class Book(db.Model):
"""
定義模型類-書名
"""
__tablename__ = 'books'
id = db.Column(db.Integer,primary_key=True)
info = db.Column(db.String(32),unique=True)
leader = db.Column(db.String(32))
au_book = db.Column(db.Integer,db.ForeignKey('author.id'))
def __str__(self):
return f'Book:{self.info},{self.lead}'
if __name__ == "__main__":
app.run()
複製程式碼開啟 flask shell 建立表：
(ihome) furuiyang@furuiyangdeMacBook-Pro ~/codes/iHomeDemo master flask shell
Python 3.7.3 (default,Jun 19 2019,07:38:49)
[Clang 10.0.1 (clang-1001.0.46.4)] on darwin
App: app [production]
Instance: /Users/furuiyang/codes/iHomeDemo/instance
>>> from app import db
>>> db.create_all()
複製程式碼在資料庫中檢視創建出的表結構：
mysql> desc author;
+-------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| name | varchar(32) | YES | UNI | NULL | |
| email | varchar(64) | YES | | NULL | |
+-------+-------------+------+-----+---------+----------------+
3 rows in set (0.01 sec)
mysql> desc books;
+---------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+---------+-------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| info | varchar(32) | YES | UNI | NULL | |
| leader | varchar(32) | YES | | NULL | |
| au_book | int(11) | YES | MUL | NULL | |
+---------+-------------+------+-----+---------+----------------+
4 rows in set (0.00 sec)
複製程式碼生成一些測試資料：
>>> au1 = Author(name='八月長安',email='[email protected]')
>>> au2 = Author(name='餘秋雨',email='[email protected]')
>>> au3 = Author(name='馮唐',email='[email protected]')
>>> bk1 = Book(info='最好的我們',leader='耿耿&餘淮')
>>> bk2 = Book(info='文化苦旅',leader='風景抒情')
>>> bk3 = Book(info='萬物生長',leader='秋水')
>>> db.session.add_all([au1,au2,au3,bk1,bk2,bk3])
>>> db.session.commit()
複製程式碼檢視資料庫：
mysql> select * from author;
+----+--------------+-----------------+
| id | name | email |
+----+--------------+-----------------+
| 1 | 八月長安 | [email protected] |
| 2 | 餘秋雨 | [email protected] |
| 3 | 馮唐 | [email protected] |
+----+--------------+-----------------+
3 rows in set (0.00 sec)
mysql> select * from books;
+----+-----------------+---------------+---------+
| id | info | leader | au_book |
+----+-----------------+---------------+---------+
| 1 | 最好的我們 | 耿耿&餘淮 | NULL |
| 2 | 文化苦旅 | 風景抒情 | NULL |
| 3 | 萬物生長 | 秋水 | NULL |
+----+-----------------+---------------+---------+
3 rows in set (0.00 sec)
複製程式碼新增一個模板展示頁面：
<h1>書籍展示</h1>
<form method="post">
{{ form.csrf_token }}
<p>作者：{{ form.au_info }}</p>
<p>書名：{{ form.bk_info }}</p>
<p>{{ form.submit }}</p>
</form>
<ul>
<li>{% for x in author %}</li>
<li>{{ x }}</li><a href='/delete_author{{ x.id }}'>刪除</a>
<li>{% endfor %}</li>
</ul>
<hr>
<ul>
<li>{% for x in book %}</li>
<li>{{ x }}</li><a href='/delete_book{{ x.id }}'>刪除</a>
<li>{% endfor %}</li>
</ul>
複製程式碼新增檢視路由：
from flask import Flask,url_for
from flask_sqlalchemy import SQLAlchemy
from flask_wtf import Form
from wtforms import StringField,SubmitField
from wtforms.validators import DataRequired
app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'mysql://root:[email protected]:3306/test'
app.config['SQLALCHEMY_COMMIT_ON_TEARDOWN'] = True
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
app.config['SECRET_KEY'] = 'ruiyang'
db = SQLAlchemy(app)
class Author(db.Model):
"""
定義模型類-作者
"""
__tablename__ = 'author'
id = db.Column(db.Integer,{self.leader}'
class Append(Form):
"""建立表單類，用來新增資訊"""
au_info = StringField(validators=[DataRequired()])
bk_info = StringField(validators=[DataRequired()])
submit = SubmitField(u'新增')
@app.route('/','POST'])
def index():
# 查詢所有作者和書名資訊
author = Author.query.all()
book = Book.query.all()
# 建立表單物件
form = Append()
if form.validate_on_submit():
# 獲取表單輸入資料
wtf_au = form.au_info.data
wtf_bk = form.bk_info.data
# 把表單資料存入模型類
db_au = Author(name=wtf_au)
db_bk = Book(info=wtf_bk)
# 提交會話
db.session.add_all([db_au,db_bk])
db.session.commit()
# 新增資料後，再次查詢所有作者和書名資訊
author = Author.query.all()
book = Book.query.all()
return render_template('index.html',author=author,book=book,form=form)
else:
if request.method == 'GET':
render_template('index.html',form=form)
return render_template('index.html',form=form)
@app.route('/delete_author<id>')
def delete_author(id):
"""刪除作者"""
# 精確查詢需要刪除的作者id
au = Author.query.filter_by(id=id).first()
db.session.delete(au)
# 直接重定向到index檢視函式
return redirect(url_for('index'))
@app.route('/delete_book<id>')
def delete_book(id):
"""刪除書名"""
# 精確查詢需要刪除的書名id
bk = Book.query.filter_by(id=id).first()
db.session.delete(bk)
# 直接重定向到index檢視函式
return redirect(url_for('index'))
if __name__ == "__main__":
app.run(debug=True)
複製程式碼在 app 中加入擴充套件
建立遷移資料庫
(ihome) ✘ furuiyang@furuiyangdeMacBook-Pro ~/codes/iHomeDemo master ●✚ flask db init
Creating directory /Users/furuiyang/codes/iHomeDemo/migrations ... done
Creating directory /Users/furuiyang/codes/iHomeDemo/migrations/versions ... done
Generating /Users/furuiyang/codes/iHomeDemo/migrations/script.py.mako ... done
Generating /Users/furuiyang/codes/iHomeDemo/migrations/env.py ... done
Generating /Users/furuiyang/codes/iHomeDemo/migrations/README ... done
Generating /Users/furuiyang/codes/iHomeDemo/migrations/alembic.ini ... done
複製程式碼建立遷移資料指令碼
(ihome) furuiyang@furuiyangdeMacBook-Pro ~/codes/iHomeDemo master ●✚ flask db migrate -m 'first'
INFO [alembic.runtime.migration] Context impl MySQLImpl.
INFO [alembic.runtime.migration] Will assume non-transactional DDL.
INFO [alembic.autogenerate.compare] Detected added table 'author'
INFO [alembic.autogenerate.compare] Detected added table 'books'
Generating /Users/furuiyang/codes/iHomeDemo/migrations/versions/947c0bffbb1b_first.py ... done
複製程式碼使用遷移指令碼更新資料庫
(ihome) furuiyang@furuiyangdeMacBook-Pro ~/codes/iHomeDemo master ●✚ flask db upgrade
INFO [alembic.runtime.migration] Context impl MySQLImpl.
INFO [alembic.runtime.migration] Will assume non-transactional DDL.
INFO [alembic.runtime.migration] Running upgrade -> 947c0bffbb1b,first
複製程式碼資料庫變動
檢視歷史版本
flask db history
複製程式碼版本回退
flask db downgrade 版本號
複製程式碼註冊shell上下文
在我們啟動 flask shell的時候，我們就實現了在上下文中啟動了一個python 直譯器。這意味著我們可以有了當前的應用例項：
使用常規的直譯器會話時，除非明確地被匯入，否則app物件是未知的，但是當使用flask shell時，該命令預先匯入應用例項。 flask shell的絕妙之處不在於它預先匯入了app，而是你可以配置一個“shell上下文”，也就是可以預先匯入一份物件列表。
在入口指令碼中實現一個函式，通過新增資料庫例項和模型來建立了一個shell上下文環境：
from app import app,db
from app.models import User,Post
@app.shell_context_processor
def make_shell_context():
return {'db': db,'User': User,'Post': Post}
複製程式碼app.shell_context_processor裝飾器將該函式註冊為一個shell上下文函式。 當flask shell命令執行時，它會呼叫這個函式並在shell會話中註冊它返回的專案。 函式返回一個字典而不是一個列表，原因是對於每個專案，你必須通過字典的鍵提供一個名稱以便在shell中被呼叫。