flask插件之flask_sqlalchemy使用
flask_sqlalchemy其实是在sqlalchemy上封装了一层适用与flask的一个插件，便于开发者在flask中更方法的操作数据库，在flask中使用flask_sqlalchemy主要是要注意目录结构
这是一个小型程序的目录结构
FlaskProject
app
__init__.py
models.py
views
login.py
middlewares.py
static
templates
settings.py
manage.pyapp->__init__.py
from flask import Flask
from flask_sqlalchemy import SQLAlchemy # 到入flask_sqlalchemy
from flask_session import Session
db = SQLAlchemy()
from .models import *
from .views.login import login
def create_app(settings_cls):
app = Flask(__name__, template_folder='templates', static_folder='statics', static_url_path='/static')
app.config.from_object(settings_cls) # 加载配文件
Session(app) # session写到redis
db.init_app(app) # 初始化数据库
app.register_blueprint(login)
return appmodels.py
from .import db
import datetime
class Users(db.Model):
__tablename__ = 'users'
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(32), index=True, nullable=False)
email = db.Column(db.String(32), unique=True)
ctime = db.Column(db.DateTime, default=datetime.datetime.now)
extra = db.Column(db.Text, nullable=True)
__table_args__ = (
db.UniqueConstraint('id', 'name', name='uix_id_name'),
db.Index('ix_id_name', 'name', 'email'),
)views->login.py
#!/usr/bin/env python
from flask import Blueprint
login = Blueprint('login', __name__, url_prefix='/login')
from ..models import *
from .middlewares import *
@login.route("/")
def login():
# ############# 执行ORM操作 #############
obj1 = Users(name="tom")
db.session.add(obj1)
# 批量增加
# db.session.add_all([
# Users(name="wupeiqi1"),
# Users(name="alex"),
# Hosts(name="c1.com"),
# ])
# 删除
# db.session.query(Users).filter(Users.id > 2).delete()
# 修改
# db.session.query(Users).filter(Users.id > 0).update({"name": "099"})
# db.session.query(Users).filter(Users.id > 0).update({Users.name: Users.name + "xxx"}, synchronize_session=False)
# db.session.query(Users).filter(Users.id > 0).update({"age": Users.age + 1}, synchronize_session="evaluate")
# ################ 查询 ################
'''
r1 = db.session.query(Users).all()
r2 = db.session.query(Users.name.label('xx'), Users.age).all()
r3 = db.session.query(Users).filter(Users.name == "alex").all()
r4 = db.session.query(Users).filter_by(name='alex').all()
r5 = db.session.query(Users).filter_by(name='alex').first()
r6 = db.session.query(Users).filter(db.text("id<:value and name=:name")).params(value=224, name='fred').order_by(Users.id).all()
r7 = db.session.query(Users).from_statement(db.text("SELECT * FROM users where name=:name")).params(name='ed').all()
'''
# 条件
# ret = db.session.query(Users).filter_by(name='alex').all()
# ret = db.session.query(Users).filter(Users.id > 1, Users.name == 'eric').all()
# ret = db.session.query(Users).filter(Users.id.between(1, 3), Users.name == 'eric').all() # 1-3之间
# # in查询
# ret = db.session.query(Users).filter(Users.id.in_([1, 3, 4])).all()
# ret = db.session.query(Users).filter(~Users.id.in_([1, 3, 4])).all() # 取非
# ret = db.session.query(Users).filter(Users.id.in_(db.session.query(Users.id).filter_by(name='eric'))).all()
# # and_ or_
# ret = db.session.query(Users).filter(db.and_(Users.id > 3, Users.name == 'eric')).all()
# ret = db.session.query(Users).filter(db.or_(Users.id < 2, Users.name == 'eric')).all()
# ret = db.session.query(Users).filter(
# db.or_(
# Users.id < 2,
# db.and_(Users.name == 'eric', Users.id > 3),
# Users.extra != ""
# )).all()
#
# # 通配符
# ret = db.session.query(Users).filter(Users.name.like('e%')).all()
# ret = db.session.query(Users).filter(~Users.name.like('e%')).all()
#
# # 限制
# ret = db.session.query(Users)[1:2]
#
# # 排序
# ret = db.session.query(Users).order_by(Users.name.desc()).all()
# ret = db.session.query(Users).order_by(Users.name.desc(), Users.id.asc()).all()
#
# # 分组
# ret = db.session.query(Users).group_by(Users.extra).all()
# ret = db.session.query(
# db.func.max(Users.id),
# db.func.sum(Users.id),
# db.func.min(Users.id)).group_by(Users.name).all()
#
# ret = session.query(
# db.func.max(Users.id),
# db.func.sum(Users.id),
# db.func.min(Users.id)).group_by(Users.name).having(db.func.min(Users.id) > 2).all()
#
# # 连表
# ret = db.session.query(Hobby, Person).filter(Person.hobby_id == Hobby.id).all()
# # 内链接
# ret = db.session.query(Person).join(Hobby).all()
# # 外连接
# ret = db.session.query(Person).join(Hobby, isouter=True).all()
#
# # 组合
# q1 = db.session.query(Person.name).filter(Person.id > 2)
# q2 = db.session.query(Hobby.caption).filter(Hobby.id < 2)
# ret = q1.union(q2).all()
#
# q1 = db.session.query(Person.name).filter(Person.id > 2)
# q2 = db.session.query(Hobby.caption).filter(Hobby.nid < 2)
# ret = q1.union_all(q2).all() # 这一句的区别
#
# # 原生sql
# cursor = db.session.execute('insert into users(name) values(:value)', params={"value": 'wupeiqi'})
# print(cursor.lastrowid)
#
# # relationship
#
# db.session.add_all([
# Hobby(caption='乒乓球'),
# Hobby(caption='羽毛球'),
# Person(name='张三', hobby_id=3),
# Person(name='李四', hobby_id=4),
# ])
#
# # 使用relationship正向查询
# v = db.session.query(Person).first()
# print(v.name)
# print(v.hobby.caption)
#
# # 使用relationship反向查询
# v = db.session.query(Hobby).first()
# print(v.caption)
# print(v.pers)
# 使用relationship增加
db.session.add(Hobby(**{'caption': '球'}))
v = db.session.query(Hobby).first()
v.pers = [Person(name="xxx"), Person(name='xxx')]
db.session.add(v)
# 其他方法增加
db.session.add(Person(name="xxx2", hobby=Hobby(**{'caption': '球'})))
# relationship各种用法，多对多查询出来的是一个对象列表
print(user_obj.role.person[0].name)
# 多对多修改
user_obj.role.person = db.session.query(Person).filter(Person.id.in_([1, 2])).all()
db.session.add(user_obj)
# 多对多增加
# db.session.add(Roles(name="普通用户"))
# obj = db.session.query(Roles).filter_by(name="普通用户").first()
# obj.person = [Person(name='删除用户'), Person(name='修改用户')]
# db.session.add(obj)
# 一对多增加用户
# db.session.add(Users(name="李晓青", email="[email protected]", password="123456", role_id=1))
# 一对多修改用户
db.session.query(Users).filter_by(name="李晓青").update({'role_id': 2})
"""
user_obj.role_id = 2
db.session.add(user_obj)
"""
# 一对多连表增加
# role为relationship名
obj = Users(name="李晓", email="[email protected]", password="123456", role=Roles(name="来宾"))
db.session.add(obj)
# 实在无解，多表联查，然后用点赋值
"""
obj = db.session.query(Users, Roles).filter(Users.role_id == Roles.id).first()
obj.Users.name = "honghong"
obj.Roles.name = "honghong"
db.session.add(obj)
"""
# 关联子查询
# subqry = db.session.query(db.func.count(Server.id).label("sid")).filter(Server.id == Group.id).correlate(
# Group).as_scalar()
# result = db.session.query(Group.name, subqry)
# 提交事务
db.session.commit()
# 关闭session
db.session.close()settings.py
#!/usr/bin/env python
from redis import Redis
class Config(object):
DEBUG = False
TESTING = False
class ProductionConfig(Config):
# flask_sqlalchemy配置数据库相关
SQLALCHEMY_DATABASE_URI = 'mysql+pymysql://root:[email protected]:3306/cust_auto_m_5644?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
# 把session写到redis中
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
SESSION_REDIS = Redis(host="127.0.0.1", port='6739')
class DevelopmentConfig(Config):
pass
class Testingconfig(Config):
TESTING = Truemanage.py
from flask_script import Manager # flask启动时参数命令插件
from flask_migrate import Migrate, MigrateCommand # 关于数据库的插件
from app import create_app, db
app = create_app("settings.ProductionConfig")
manager = Manager(app)
# 操作数据库
migrate = Migrate(app, db)
manager.add_command('db', MigrateCommand)
"""
数据库迁移命令
python manage.py db init
python manage.py db migrate
python manage.py db upgrade
"""
@manager.command
def init_db():
with app.app_context():
db.create_all()
'''
# 方式二 Redis
from flask_session import RedisSessionInterface
from redis import Redis
redis = Redis(host="127.0.0.1")
"""
key_prefix 前缀
use_signer 是否使用签名
permanent 为False，cookie为关闭浏览器失效
"""
app.session_interface = RedisSessionInterface(redis=redis, key_prefix="__")
'''
if __name__ == "__main__":
manager.run()