Flask-SQLAlchemy.........>model创建表

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()

# ##################### 单表示例 #########################
class Users(Base):
__tablename__ = 'users'

id = Column(Integer, primary_key=True)
name = Column(String(32), index=True)
age = Column(Integer, default=18)
email = Column(String(32), unique=True)
ctime = Column(DateTime, default=datetime.datetime.now)
extra = Column(Text, nullable=True)

__table_args__ = (
UniqueConstraint('id', 'name', name='uix_id_name'),
# Index('ix_id_name', 'name', 'extra'),
)

class Hosts(Base):
__tablename__ = 'hosts'

id = Column(Integer, primary_key=True)
name = Column(String(32), index=True)
ctime = Column(DateTime, default=datetime.datetime.now)

# ##################### 一对多示例 #########################
class Hobby(Base):
__tablename__ = 'hobby'
id = Column(Integer, primary_key=True)
caption = Column(String(50), default='篮球')

class Person(Base):
__tablename__ = 'person'
nid = Column(Integer, primary_key=True)
name = Column(String(32), index=True, nullable=True)
hobby_id = Column(Integer, ForeignKey("hobby.id"))

# 与生成表结构无关，仅用于查询方便
hobby = relationship("Hobby", backref='pers')

# ##################### 多对多示例 #########################

class Server2Group(Base):
__tablename__ = 'server2group'
id = Column(Integer, primary_key=True, autoincrement=True)
server_id = Column(Integer, ForeignKey('server.id'))
group_id = Column(Integer, ForeignKey('group.id'))

class Group(Base):
__tablename__ = 'group'
id = Column(Integer, primary_key=True)
name = Column(String(64), unique=True, nullable=False)

# 与生成表结构无关，仅用于查询方便
servers = relationship('Server', secondary='server2group', backref='groups')

class Server(Base):
__tablename__ = 'server'

id = Column(Integer, primary_key=True, autoincrement=True)
hostname = Column(String(64), unique=True, nullable=False)

def init_db():
"""
根据类创建数据库表
:return:
"""
engine = create_engine(
"mysql+pymysql://root:123456@47.93.252.50:3306/userinfo?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.create_all(engine)

def drop_db():
"""
根据类删除数据库表
:return:
"""
engine = create_engine(
"mysql+pymysql://root:123456@47.93.252.50:3306/userinfo?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)

if __name__ == '__main__':
drop_db()
init_db()