flask框架4 表单验证, 表单查询wtforms，flask-migrate

简单的表单验证      wtforms

简单的表单验证.py

from flask import Flask, render_template, request, redirect
from wtforms import Form
from wtforms.fields import simple
from wtforms import validators
from wtforms import widgets

app = Flask(__name__, template_folder='templates')

app.debug = True


class LoginForm(Form):
    # 字段（内部包含正则表达式）
    name = simple.StringField(
        label='用户名',
        validators=[    # 检验规则
            validators.DataRequired(message='用户名不能为空.'),    # 错误信息
            validators.Length(min=6, max=18, message='用户名长度必须大于%(min)d且小于%(max)d')
        ],
        widget=widgets.TextInput(), # 页面上显示的插件类型
        render_kw={'class': 'form-control'} # 设定类属性，form-control 填满

    )
    # 字段（内部包含正则表达式）
    pwd = simple.PasswordField(
        label='密码',
        validators=[
            validators.DataRequired(message='密码不能为空.'),
            validators.Length(min=8, message='用户名长度必须大于%(min)d'),
            validators.Regexp(regex="^(?=.*[a-z])(?=.*[A-Z])(?=.*d)(?=.*[$@$!%*?&])[A-Za-zd$@$!%*?&]{8,}",
                              message='密码至少8个字符，至少1个大写字母，1个小写字母，1个数字和1个特殊字符')

        ],
        widget=widgets.PasswordInput(),
        render_kw={'class': 'form-control'}
    )


@app.route('/login', methods=['GET', 'POST'])
def login():
    if request.method == 'GET':
        form = LoginForm()
        return render_template('login.html', form=form)
    else:
        form = LoginForm(formdata=request.form)    # request.form接收到的表单数据
        if form.validate(): # 判断数据是否合法
            print('用户提交数据通过格式验证，提交的值为：', form.data)
        else:
            print(form.errors)
        return render_template('login.html', form=form)

if __name__ == '__main__':
    app.run()

login.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<h1>登录</h1>
<form method="post">
    <p>{{form.name.label}} {{form.name}} {{form.name.errors[0] }}</p>

    <p>{{form.pwd.label}} {{form.pwd}} {{form.pwd.errors[0] }}</p>
    <input type="submit" value="提交">
</form>
</body>
</html>

 

复杂的表单验证

复杂的表单验证.py

from flask import Flask, render_template, request, redirect
from wtforms import Form
from wtforms.fields import core
from wtforms.fields import html5
from wtforms.fields import simple
from wtforms import validators
from wtforms import widgets

app = Flask(__name__, template_folder='templates')
app.debug = True

class RegisterForm(Form):

    def validate_pwd_confirm (self, field): # 钩子
        """
        自定义pwd_confirm字段规则，例：与pwd字段是否一致
        :param field:
        :return:
        """
        # 最开始初始化时，self.data中已经有所有的值

        if field.data != self.data['pwd']:  # field指代钩子函数中的pwd_confirm，所有数据都在self.data中
            raise validators.ValidationError("密码不一致") # 继续后续验证
            #raise validators.StopValidation("密码不一致123123123")  # 不再继续后续验证，不会执行下面的pwd_confirm equalto方法

    name = simple.StringField(
        label='用户名',
        validators=[
            validators.DataRequired()
        ],
        widget=widgets.TextInput(),
        render_kw={'class': 'form-control'},
        default='alex'  # 默认值
    )

    pwd = simple.PasswordField(
        label='密码',
        validators=[
            validators.DataRequired(message='密码不能为空.')
        ],
        widget=widgets.PasswordInput(),
        render_kw={'class': 'form-control'}
    )

    pwd_confirm = simple.PasswordField(
        label='重复密码',
        validators=[
            #validators.DataRequired(message='重复密码不能为空.'),
            validate_pwd_confirm,
            validators.EqualTo('pwd', message="两次密码输入不一致")  # 判断是否和pwd相等
        ],
        widget=widgets.PasswordInput(),
        render_kw={'class': 'form-control'}
    )

    email = html5.EmailField(
        label='邮箱',
        validators=[
            validators.DataRequired(message='邮箱不能为空.'),
            validators.Email(message='邮箱格式错误')
        ],
        widget=widgets.TextInput(input_type='email'),
        render_kw={'class': 'form-control'}
    )

    gender = core.RadioField(
        label='性别',
        choices=(
            (1, '男'),
            (2, '女'),
        ),
        coerce=int # “1” “2”    # 强制为int类型
     )
    city = core.SelectField(
        label='城市',
        choices=(
            ('bj', '北京'),
            ('sh', '上海'),
        )
    )

    hobby = core.SelectMultipleField(
        label='爱好',
        choices=(
            (1, '篮球'),
            (2, '足球'),
        ),
        coerce=int
    )

    favor = core.SelectMultipleField(
        label='喜好',
        choices=(
            (1, '篮球'),
            (2, '足球'),
        ),
        widget=widgets.ListWidget(prefix_label=False),
        option_widget=widgets.CheckboxInput(),
        coerce=int,
        default=[1, 2]
    )

    # def __init__(self, *args, **kwargs):
    #     super(RegisterForm, self).__init__(*args, **kwargs)
    #     self.favor.choices = ((1, '篮球'), (2, '足球'), (3, '羽毛球'))

@app.route('/register', methods=['GET', 'POST'])
def register():
    if request.method == 'GET':
        form = RegisterForm() # initial
        return render_template('register.html', form=form)
    else:
        form = RegisterForm(formdata=request.form)  # request.form接收到的表单数据
        if form.validate():
            print('用户提交数据通过格式验证，提交的值为：', form.data)
        else:
            print(form.errors)
        return render_template('register.html', form=form)


if __name__ == '__main__':
    app.run()

register.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<h1>用户注册</h1>
<form method="post" novalidate style="padding:0  50px">
    {% for field in form %}
    <p>{{field.label}}: {{field}} {{field.errors[0] }}</p>
    {% endfor %}
    <input type="submit" value="提交">
</form>
</body>
</html>

 

flask的ORM  sqlalchemy

SQLAlchemy是一个基于Python实现的ORM框架。该框架建立在 DB API之上，使用关系对象映射进行数据库操作，简言之便是：将类和对象转换成SQL，然后使用数据API执行SQL并获取执行结果。

SQLAlchemy本身无法操作数据库，其必须以来pymsql等第三方插件，Dialect用于和数据API进行交流，根据配置文件的不同调用不同的数据库API，从而实现对数据库的操作

注意：sqlalchemy不支持改表，只能删除表后再创表

简单的表单查询

models文件：

import datetime
from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import Column, Integer, String, Text, ForeignKey, DateTime, UniqueConstraint, Index
from sqlalchemy.orm import relationship
Base = declarative_base()

class Users(Base):
    __tablename__ = 'users'  # 数据库表名称
    id = Column(Integer, primary_key=True)  # id 主键
    name = Column(String(32), index=True, nullable=False)  # name列，index索引，不可为空
    age = Column(Integer)
    # email = Column(String(32), unique=True)
    #datetime.datetime.now不能加括号，加了括号，以后永远是当前时间
    # ctime = Column(DateTime, default=datetime.datetime.now)
    # extra = Column(Text, nullable=True)

    __table_args__ = (
        # UniqueConstraint('id', 'name', name='uix_id_name'), #联合唯一
        # Index('ix_id_name', 'name', 'email'), #索引
    )

    def __repr__(self): # 更为底层，如果为__str__不能清晰显示
        return self.name

class Hobby(Base):
    __tablename__ = 'hobby'
    id = Column(Integer,primary_key=True)
    caption = Column(String(50),default='双色球')

class Person(Base):
    __tablename__ = 'person'
    nid = Column(Integer,primary_key=True)
    name = Column(String(32))
    # hobby是tablename而不是Hobby类名
    hobby_id = Column(Integer,ForeignKey('hobby.id'))

    # 更新数据库没有关系，不会信增加字段，只能用于快速的链表查询操作
    # relationship的第一个参数，是类名，第二个参数backref,用于反向查询
    hobby = relationship('Hobby',backref='pres')
    def __repr__(self):
        return self.name

class Boy2Girl(Base):
    __tablename__ = 'boy2girl'
    id = Column(Integer,primary_key=True)
    girl_id = Column(Integer,ForeignKey('girl.id'))
    boy_id = Column(Integer,ForeignKey('boy.id'))

class Girl(Base):
    __tablename__ = 'girl'
    id = Column(Integer,primary_key=True)
    name = Column(String(100),nullable=False)

    def __repr__(self):
        return self.name

class Boy(Base):
    __tablename__ = 'boy'
    id = Column(Integer,primary_key=True)
    name = Column(String(100),nullable=False)
    # secondary=boy2girl 为中间表的表名
    girl = relationship('Girl',secondary='boy2girl',backref='boys')

    def __repr__(self):
        return self.name

def init_db():
    """
    根据类创建数据库表
    :return:
    """
    engine = create_engine(
        "mysql+pymysql://root:@127.0.0.1:3306/day95?charset=utf8",
        # "什么数据库（mysql,orcal）+用什么取链接数据库（pymysql）://数据库用户名:密码@mysqlip:端口/数据库名？charset=字符集"
        max_overflow=0,  # 超过连接池大小外最多创建的连接
        pool_size=5,  # 连接池大小
        pool_timeout=30,  # 池中没有线程最多等待的时间，否则报错
        pool_recycle=-1  # 多久之后对线程池中的线程进行一次连接的回收（重置）
    )

    Base.metadata.create_all(engine)    # 创建数据库

def drop_db():
    """
    根据类删除数据库表
    :return:
    """
    engine = create_engine(
        "mysql+pymysql://root:@127.0.0.1:3306/day95?charset=utf8",
        max_overflow=0,  # 超过连接池大小外最多创建的连接
        pool_size=5,  # 连接池大小
        pool_timeout=30,  # 池中没有线程最多等待的时间，否则报错
        pool_recycle=-1  # 多久之后对线程池中的线程进行一次连接的回收（重置）
    )

    Base.metadata.drop_all(engine)  # 删除数据库

if __name__ == '__main__':  # sqlalchemy不支持该表，只能删除表后再创表
    drop_db()
    init_db()

orm.py

from sqlalchemy.orm import sessionmaker
from sqlalchemy import create_engine
from models import Users
#"mysql+pymysql://root@127.0.0.1:3306/aaa"
engine = create_engine("mysql+pymysql://root:@127.0.0.1:3307/python13", max_overflow=0, pool_size=5)
Connection = sessionmaker(bind=engine)

# 每次执行数据库操作时，都需要创建一个Connection
con = Connection()

# 1 单增

# obj1  = Users(name="lsb1",age=12)
# con.add(obj1)

# 2 多个增加

# con.add_all([
#          Users(name="lsb1",age=12),
#         Users(name="esb",age=40),
#         Users(name="jsb",age=30),
#         Users(name="tsb",age=12),
#         #Host(name = "tsb",time=123213)
# ])



# 3 删除
# con.query(Users).delete()


#4 改
# con.query(Users).update({"name":"sb","age":14})    # 要传字典

# 如果拼接是字符串，此处要设置synchronize_session=False
# con.query(Users).update({Users.name:Users.name +" is true","age":1},synchronize_session=False)

# con.query(Users).update({Users.age:Users.age + 10})

# 5查(查是不需要commit,也能拿到结果)
#打印sql
# r1 = con.query(Users)

#查询所有
# r1 = con.query(Users).all()
#
#查单条记录
# r1  = con.query(Users).first()

#查哪些字段
# r1  = con.query(Users.age,Users.name.label("sb")).first()    # 起别名sb 打印要用print(r1.sb)

#过滤用filter_by(传参数)或者filter（传表达式）
# r1 = con.query(Users).filter(Users.name == "tsb").first()
# con.query(Users).filter(Users.name == "tsb").update({"name": "sb", "age": 14})


r1 =  con.query(Users).filter_by(name = "esb").first()

print(r1)

#必须提交才能生效
con.commit()

#关闭链接
con.close()

单表查询

from sqlalchemy.orm import sessionmaker
from sqlalchemy import create_engine
from models import Users
#"mysql+pymysql://root@127.0.0.1:3306/aaa"
engine = create_engine("mysql+pymysql://root:@127.0.0.1:3307/python13", max_overflow=0, pool_size=5)
Connection = sessionmaker(bind=engine)

# 每次执行数据库操作时，都需要创建一个Connection
session = Connection()

# 条件
# ret =  session.query(Users).filter_by(name = "esb").all()

#表达式，and 条件链接
# ret  = session.query(Users).filter(Users.name == "sb",Users.age ==14 ).first()
# print(ret.age,ret.name)

# 表示的between，条件,30<=age<=40
# ret  = session.query(Users).filter(Users.age.between(30,40)).all()
# print(ret)

# sql查询的in_操作,相当于django中的__in
# ret =session.query(Users).filter(Users.id.in_([9,11,13])).all()
# print(ret)
# # sql查询取反
# ret1 = session.query(Users).filter(~Users.id.in_([9,11,13])).all()
# print(ret1)


#or查询 ，or和and ,做整合
from sqlalchemy import or_,and_

# ret =  session.query(Users).filter(or_(Users.id == 9,Users.name=="jsb")).all()
# ret =  session.query(Users).filter(and_(Users.id == 9,Users.name=="lsb1")).all()

# ret =  session.query(Users).filter(or_(
#     Users.id == 9,
#     and_(Users.name=="jsb",Users.id==13),
#
#     )
# ).all()

# like查询,        # _代表一个字符，%代表任意字符
#必须以b开头
# ret = session.query(Users).filter(Users.name.like("b%")).all()
# #第二字母是b
# ret = session.query(Users).filter(Users.name.like("_b%")).all()
#不以b开头
# ret = session.query(Users).filter(~Users.name.like("b%")).all()

#排序
#desc重大到小排序
# ret = session.query(Users).filter(Users.id>1).order_by(Users.id.desc()).all()
#desc重小到大排序
#ret = session.query(Users).filter(Users.id>1).order_by(Users.id.asc()).all()
#多条件排序,先以年纪从大到小排，如果年龄相同，再以id从小到大排
# ret = session.query(Users).filter(Users.id>1).order_by(Users.age.desc(),Users.id.asc()).all()
# print(ret)


#分组查询
# ret  = session.query(Users).group_by(Users.name).all()

# 再分组的时候如果要用聚合操作，就要导入func
from sqlalchemy.sql import func
#选出组内最小年龄要大于等于30的组
# ret  = session.query(Users).group_by(Users.name).having(func.min(Users.age)>=30).all()

#选出组内最小年龄要大于等于30的组,查询组内的最小年龄，最大年纪，年纪之和，
ret = session.query(
    func.min(Users.age),    # 显示组中最小值
    func.max(Users.age),
    func.sum(Users.age),
    Users.name
).group_by(Users.name).having(func.min(Users.age)>=30).all()
print(ret)

一对多关联

from sqlalchemy.orm import sessionmaker
from sqlalchemy import create_engine
from models import Hobby,Person
#"mysql+pymysql://root@127.0.0.1:3306/aaa"
engine = create_engine("mysql+pymysql://root:@127.0.0.1:3307/python13", max_overflow=0, pool_size=5)
Connection = sessionmaker(bind=engine)

# 每次执行数据库操作时，都需要创建一个Connection
session = Connection()

#1添加,没有用关联关系
# session.add_all([
#     Hobby(catption="淫诗"),
#     Hobby(catption="推背"),
#     Person(name="tank",hobby_id=1),
#     Person(name="jason",hobby_id=2)
# ])

# 2添加 用关联关系
# preson = Person(name="egon",hobby=Hobby(catption="相亲"))
#session.add(preson)
#
# hobb = Hobby(catption="人妖")
# hobb.pres = [Person(name="owen"),Person(name="sean")]
# session.add(hobb)

#session.commit()

#正向查询
# pr = session.query(Person).filter( Person.name == "tank").first()
# print(pr.name)
# print(pr.hobby.catption)


#反向查
# v = session.query(Hobby).filter(Hobby.catption=="人妖").first()
# print(v.catption)
# print(v.pres)


# 如果没用foreign key,为断关联。自己连表,isouter=True表示是left join，不填默认为inner join
person_list =  session.query( Hobby).join(Person,Person.hobby_id==Hobby.id,isouter=True)
#
print(person_list)


session.close()

多对多

from sqlalchemy.orm import sessionmaker
from sqlalchemy import create_engine
from models import Boy,Boy2Girl,Girl
#"mysql+pymysql://root@127.0.0.1:3306/aaa"
engine = create_engine("mysql+pymysql://root:@127.0.0.1:3307/python13", max_overflow=0, pool_size=5)
Connection = sessionmaker(bind=engine)

# 每次执行数据库操作时，都需要创建一个Connection
session = Connection()

#添加
# session.add_all([    
#     Boy(name="tank"),
#     Boy(name="sean"),
#     Girl(name="仓老师"),
#     Girl(name="小泽老师")
# ])

# b2g = Boy2Girl(boy_id=1,girl_id=2)
# session.add(b2g )
# b2g = Boy2Girl(boy_id=2,girl_id=1)
# session.add(b2g )
# session.commit()
# session.close()

# 关联添加
# boy = Boy(name="亚峰")
# boy.girl=[Girl(name="迪丽热巴"),Girl(name="三上")]
# session.add(boy)
# session.commit()

#
# girl = Girl(name="丹丹")
# girl.boys=[Boy(name="吴彦祖"),Boy(name="鹿晗")]
# session.add(girl)
# session.commit()

# 使用relationship的关系，正向查
# b = session.query(Boy).filter(Boy.name == "亚峰").first()
# print(b.name)
# print(b.girl)

#反向查询
# g = session.query(Girl).filter(Girl.name=="丹丹").first()
# print(g.name)
# print(g.boys)

flask-migrate

 flask_sqlalchemy是flask和SQLAchemy的管理者，通过他把他们做连接的ORM

flask_sqlalchemy 

要用就必须先安装。
pip install flask-sqlalchemy
所有的到导入都找 下面的db
from flask_sqlalchemy import SQLAlchemy
db = SQLAlchemy()

flask_migrate       数据库迁移命令

安装
pip install flask-migrate

命令：manager.add_command('db1', MigrateCommand)
1 当项目第一次执行迁移的时候。
python3 manage.py db1 init 只需要初始化一次

2 python3 manage.py db1 migrate # 等同于django的makemigrations

3 python3 manage.py db1 upgrade # 等同于django的migrate

启动项目 python manage.py runserver

示例：

settings.py

class BaseConfig(object):
    # SESSION_TYPE = 'redis'  # session类型为redis
    # SESSION_KEY_PREFIX = 'session:'  # 保存到session中的值的前缀
    # SESSION_PERMANENT = True  # 如果设置为False，则关闭浏览器session就失效。
    # SESSION_USE_SIGNER = False  # 是否对发送到浏览器上 session:cookie值进行加密

    SQLALCHEMY_DATABASE_URI = "mysql+pymysql://root:@127.0.0.1:3306/day95?charset=utf8"
    SQLALCHEMY_POOL_SIZE = 5
    SQLALCHEMY_POOL_TIMEOUT = 30
    SQLALCHEMY_POOL_RECYCLE = -1

    # 追踪对象的修改并且发送信号
    SQLALCHEMY_TRACK_MODIFICATIONS = False

manage.py

"""
必须 pip install flask-migrate,,为管理数据库的版本
flask-sqlalchemy,这个orm

"""

from sansa import create_app
from flask_script import Manager
# flask_migrate管理数据迁移的
from flask_migrate import Migrate,MigrateCommand
from sansa import db
app = create_app()
manager=Manager(app)

# 将当前app,与db注册到Migrate
Migrate(app,db)
# 添加管理数据的命令
manager.add_command('db1', MigrateCommand)

if __name__ == '__main__':
    # app.run()
    manager.run()

sansa/models.py

from . import db

class Users(db.Model):
    """
    用户表
    """
    __tablename__ = 'users'
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(80), unique=True, nullable=False)
    email = db.Column(db.String(120), unique=True, nullable=False)
    ids = db.Column(db.Integer)

    def __repr__(self):
        return '<User %r>' % self.username

sansa/__init__.py

from flask import Flask
from flask_sqlalchemy import SQLAlchemy
db = SQLAlchemy()

# from .models import *
from .views import account

def create_app():
    app = Flask(__name__)
    app.config.from_object('settings.BaseConfig')

    # 将db注册到app中
    db.init_app(app)

    # 注册蓝图
    app.register_blueprint(account.account)

    return app

sansa/views/account.py

from flask import Blueprint
from .. import db
from .. import models

account = Blueprint('account', __name__)

@account.route('/login')
def login():
    # db.session.add(models.Users(username='lqz', email='123'))
    #db.session.query(models.Users).all()
    # db.session.commit()
    # 添加示例
   
    user_list = db.session.query(models.Users).all()

    for item in user_list:
        print(item.username,"is",item.email)

    return 'login'
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原文地址：https://www.cnblogs.com/ludingchao/p/12554879.html