1、unique = True 表示启动唯一索
2、有add 必须有commit这样数据才会提交
3、ORM功能
#!/usr/bin/env python # -*- coding:utf-8 -*- from sqlalchemy.ext.declarative import declarative_base from sqlalchemy import Column, Integer, String, ForeignKey, UniqueConstraint, Index from sqlalchemy.orm import sessionmaker, relationship from sqlalchemy import create_engine engine = create_engine("mysql+pymysql://root:123@127.0.0.1:3306/t1", max_overflow=5) Base = declarative_base() # 创建单表 class Users(Base): __tablename__ = 'users' id = Column(Integer, primary_key=True) name = Column(String(32)) extra = Column(String(16)) __table_args__ = ( UniqueConstraint('id', 'name', name='uix_id_name'), Index('ix_id_name', 'name', 'extra'), ) # 一对多 class Favor(Base): __tablename__ = 'favor' nid = Column(Integer, primary_key=True) caption = Column(String(50), default='red', unique=True) class Person(Base): __tablename__ = 'person' nid = Column(Integer, primary_key=True) name = Column(String(32), index=True, nullable=True) favor_id = Column(Integer, ForeignKey("favor.nid")) # 多对多 class Group(Base): __tablename__ = 'group' id = Column(Integer, primary_key=True) name = Column(String(64), unique=True, nullable=False) port = Column(Integer, default=22) class Server(Base): __tablename__ = 'server' id = Column(Integer, primary_key=True, autoincrement=True) hostname = Column(String(64), unique=True, nullable=False) class ServerToGroup(Base): __tablename__ = 'servertogroup' nid = Column(Integer, primary_key=True, autoincrement=True) server_id = Column(Integer, ForeignKey('server.id')) group_id = Column(Integer, ForeignKey('group.id')) def init_db(): Base.metadata.create_all(engine) def drop_db(): Base.metadata.drop_all(engine)
#!/usr/bin/env python # -*- coding:utf-8 -*- from sqlalchemy.ext.declarative import declarative_base from sqlalchemy import Column, Integer, String, ForeignKey, UniqueConstraint, Index from sqlalchemy.orm import sessionmaker, relationship from sqlalchemy import create_engine engine = create_engine("mysql+pymysql://root:123@127.0.0.1:3306/t1", max_overflow=5) Base = declarative_base() # 创建单表 class Users(Base): __tablename__ = 'users' id = Column(Integer, primary_key=True) name = Column(String(32)) extra = Column(String(16)) __table_args__ = ( UniqueConstraint('id', 'name', name='uix_id_name'), Index('ix_id_name', 'name', 'extra'), ) def __repr__(self): return "%s-%s" %(self.id, self.name) # 一对多 class Favor(Base): __tablename__ = 'favor' nid = Column(Integer, primary_key=True) caption = Column(String(50), default='red', unique=True) def __repr__(self): return "%s-%s" %(self.nid, self.caption) class Person(Base): __tablename__ = 'person' nid = Column(Integer, primary_key=True) name = Column(String(32), index=True, nullable=True) favor_id = Column(Integer, ForeignKey("favor.nid")) # 与生成表结构无关,仅用于查询方便 favor = relationship("Favor", backref='pers') # 多对多 class ServerToGroup(Base): __tablename__ = 'servertogroup' nid = Column(Integer, primary_key=True, autoincrement=True) server_id = Column(Integer, ForeignKey('server.id')) group_id = Column(Integer, ForeignKey('group.id')) group = relationship("Group", backref='s2g') server = relationship("Server", backref='s2g') class Group(Base): __tablename__ = 'group' id = Column(Integer, primary_key=True) name = Column(String(64), unique=True, nullable=False) port = Column(Integer, default=22) # group = relationship('Group',secondary=ServerToGroup,backref='host_list') class Server(Base): __tablename__ = 'server' id = Column(Integer, primary_key=True, autoincrement=True) hostname = Column(String(64), unique=True, nullable=False) def init_db(): Base.metadata.create_all(engine) def drop_db(): Base.metadata.drop_all(engine) Session = sessionmaker(bind=engine) session = Session() 表结构 + 数据库连接
#增 obj = Users(name="alex0", extra='sb') session.add(obj) session.add_all([ Users(name="alex1", extra='sb'), Users(name="alex2", extra='sb'), ]) session.commit() #删 session.query(Users).filter(Users.id > 2).delete() session.commit() #改 session.query(Users).filter(Users.id > 2).update({"name" : "099"}) session.query(Users).filter(Users.id > 2).update({Users.name: Users.name + "099"}, synchronize_session=False) session.query(Users).filter(Users.id > 2).update({"num": Users.num + 1}, synchronize_session="evaluate") session.commit() #查 ret = session.query(Users).all() ret = session.query(Users.name, Users.extra).all() ret = session.query(Users).filter_by(name='alex').all() ret = session.query(Users).filter_by(name='alex').first() ret = session.query(Users).filter(text("id<:value and name=:name")).params(value=224, name='fred').order_by(User.id).all() ret = session.query(Users).from_statement(text("SELECT * FROM users where name=:name")).params(name='ed').all() #其他 # 条件 ret = session.query(Users).filter_by(name='alex').all() ret = session.query(Users).filter(Users.id > 1, Users.name == 'eric').all() ret = session.query(Users).filter(Users.id.between(1, 3), Users.name == 'eric').all() ret = session.query(Users).filter(Users.id.in_([1,3,4])).all() ret = session.query(Users).filter(~Users.id.in_([1,3,4])).all() ret = session.query(Users).filter(Users.id.in_(session.query(Users.id).filter_by(name='eric'))).all() from sqlalchemy import and_, or_ ret = session.query(Users).filter(and_(Users.id > 3, Users.name == 'eric')).all() ret = session.query(Users).filter(or_(Users.id < 2, Users.name == 'eric')).all() ret = session.query(Users).filter( or_( Users.id < 2, and_(Users.name == 'eric', Users.id > 3), Users.extra != "" )).all() # 通配符 ret = session.query(Users).filter(Users.name.like('e%')).all() ret = session.query(Users).filter(~Users.name.like('e%')).all() # 限制 ret = session.query(Users)[1:2] # 排序 ret = session.query(Users).order_by(Users.name.desc()).all() ret = session.query(Users).order_by(Users.name.desc(), Users.id.asc()).all() # 分组 from sqlalchemy.sql import func ret = session.query(Users).group_by(Users.extra).all() ret = session.query( func.max(Users.id), func.sum(Users.id), func.min(Users.id)).group_by(Users.name).all() ret = session.query( func.max(Users.id), func.sum(Users.id), func.min(Users.id)).group_by(Users.name).having(func.min(Users.id) >2).all() # 连表 ret = session.query(Users, Favor).filter(Users.id == Favor.nid).all() ret = session.query(Person).join(Favor).all() ret = session.query(Person).join(Favor, isouter=True).all() # 组合 q1 = session.query(Users.name).filter(Users.id > 2) q2 = session.query(Favor.caption).filter(Favor.nid < 2) ret = q1.union(q2).all() q1 = session.query(Users.name).filter(Users.id > 2) q2 = session.query(Favor.caption).filter(Favor.nid < 2) ret = q1.union_all(q2).all()
条件用 filter单值用filter_by
4、示例代码
#!/usr/bin/env python # -*- coding:utf-8 -*- #coding:utf8 import sqlalchemy from sqlalchemy import create_engine from sqlalchemy.ext.declarative import declarative_base from sqlalchemy import Column, Integer, String from sqlalchemy.orm import sessionmaker print(sqlalchemy.__version__) engine = create_engine('mysql+pymysql://sysadmin:password01!@10.10.8.12:3306/q2') Base = declarative_base()#生成一个SQLORM基类 class User(Base): __tablename__ = 'sqlalchemydemo' id = Column(Integer, primary_key=True, autoincrement=True) name = Column(String(40)) fullname = Column(String(40)) password = Column(String(40)) def __repr__(self): return "<User(name='%s', fullname='%s', password='%s')>" % ( self.name, self.fullname, self.password) Base.metadata.create_all(engine) #创建所有表结构 # Base.metadata.drop_all(engine) # 删除所有表 # ed_user = User(name='xiaoyu', fullname='Xiaoyu Liu', password='123') # print(ed_user) # #这两行触发sessionmaker类下的__call__方法,return得到 Session实例,赋给变量session,所以session可以调用Session类下的add,add_all等方法 MySession = sessionmaker(bind=engine) session = MySession() # session.add(ed_user) ##添加数据 # our_user = session.query(User).filter_by(name='ed').first() # SELECT * FROM users WHERE name="ed" LIMIT 1; # session.add_all([ # User(name='alex', fullname='Alex Li', password='456'), # User(name='alex', fullname='Alex old', password='789'), # User(name='peiqi', fullname='Peiqi Wu', password='sxsxsx')]) # # session.commit() #print(">>>",session.query(User).filter_by(name='ed').first()) # print(session.query(User).all()) #表内容 # for row in session.query(User).order_by(User.id): # print(row) # for row in session.query(User).filter(User.name.in_(['alex', 'wendy', 'jack'])):#这里的名字是完全匹配 # print(row) # for row in session.query(User).filter(~User.name.in_(['ed', 'wendy', 'jack'])): # print(row) # print(session.query(User).filter(User.name == 'ed').count()) from sqlalchemy import and_, or_ # for row in session.query(User).filter(and_(User.name == 'ed', User.fullname == 'Ed Jones')): # print(row) for row in session.query(User).filter(or_(User.name == 'ed', User.fullname == 'wendy')): print(row)
#!/usr/bin/env python # -*- coding:utf-8 -*- from sqlalchemy.ext.declarative import declarative_base from sqlalchemy import Column, Integer, String, ForeignKey, UniqueConstraint, Index from sqlalchemy.orm import sessionmaker, relationship from sqlalchemy import create_engine engine = create_engine('mysql+pymysql://sysadmin:password01!@10.10.8.12:3306/q2') Base = declarative_base() class Son(Base): __tablename__ = 'son' id = Column(Integer, primary_key=True) name = Column(String(32)) age = Column(String(16)) father_id = Column(Integer, ForeignKey('father.id')) # father = relationship('Father') # __table_args__ = ( # UniqueConstraint('id', 'name', name='uix_id_name'), # Index('ix_id_name', 'name', 'extra'), # ) # class Father(Base): __tablename__ = 'father' id = Column(Integer, primary_key=True) name = Column(String(32)) age = Column(String(16)) son = relationship('Son', backref = 'father') Base.metadata.create_all(engine) Session = sessionmaker(bind=engine) session = Session() # ret3 = session.query(Father).filter_by(id=1).all() # ret4 = session.query(Father).filter_by(id=4).first() # for ii in ret4.son: # print(ii.name) # s1 = session.query(Son).filter_by(id=1).first() # print(s1.father.name,s1.name) ret4 = session.query(Father).filter_by(id=4).first() w4 = Son(name = 'little alvin4',age = 5) ret4.son.append(w4) session.add(ret4) session.commit() # print(ret3) # for i in ret3: # print(i.name) # # ret1 = session.query(Father.name.label('kkk'), Son.name.label('ppp')).join(Son) # # ret = session.query(Father.name.label('kkk'), Son.name.label('ppp')).join(Son).all() # print(ret1) # print(ret) # # print(len(ret)) # for ii in ret: # print(ii) # # f1 = Father(name='alvin4', age=50) # w1 = Son(name='little alvin1', age=4, father_id = 2) # w2 = Son(name='little alvin2', age=5, father_id = 2) # # # # f1.son = [w1, w2] # # session.add(f1) # # session.add_all([w1,w2]) # session.commit()
#!/usr/bin/env python # -*- coding:utf-8 -*- from sqlalchemy.ext.declarative import declarative_base from sqlalchemy import Column, Integer, String, ForeignKey, UniqueConstraint, Index from sqlalchemy.orm import sessionmaker, relationship from sqlalchemy import create_engine engine = create_engine('mysql+pymysql://sysadmin:password01!@10.10.8.12:3306/q2?charset=utf8') Base = declarative_base() class Men_to_Wemon1(Base): __tablename__ = 'men_to_wemon1' nid = Column(Integer, primary_key=True) men_id = Column(Integer, ForeignKey('men1.id')) women_id = Column(Integer, ForeignKey('women1.id')) class Men1(Base): __tablename__ = 'men1' id = Column(Integer, primary_key=True) name = Column(String(32)) age= Column(String(16)) class Women1(Base): __tablename__ ='women1' id = Column(Integer, primary_key=True) name = Column(String(32)) age= Column(String(16)) bf=relationship("Men1",secondary=Men_to_Wemon1.__table__,backref='gf') Base.metadata.create_all(engine) # Session = sessionmaker(bind=engine) session = Session() # # m1=Men1(name='alex',age=18) # m2=Men1(name='wusir',age=18) # w1=Women1(name='如花',age=40) # w2=Women1(name='铁锤',age=45) # t1 = Men_to_Wemon1(men_id=1,women_id=2) m1 = session.query(Men1).filter_by(id = 2).first() w1 = session.query(Women1).all() m1.gf=w1 # m1.gf=[w1,w2] # w1.bf=[m1,m2] session.add_all([m1,]) # session.add_all([m1,m2,w1,w2]) # session.add(t1) session.commit()
#!/usr/bin/env python # -*- coding:utf-8 -*- from sqlalchemy import create_engine, and_, or_, func, Table from sqlalchemy.ext.declarative import declarative_base from sqlalchemy import Column, Integer, String, ForeignKey from sqlalchemy.orm import sessionmaker, relationship engine = create_engine('mysql+pymysql://sysadmin:password01!@10.10.8.12:3306/q2?charset=utf8') Base = declarative_base() # 生成一个SqlORM 基类 class HostToGroup(Base): __tablename__ = 'host_2_group' nid = Column(Integer, primary_key=True) host_id = Column(Integer, ForeignKey("host.id")) group_id = Column(Integer, ForeignKey("group.id")) class Host(Base): __tablename__ = 'host' id = Column(Integer, primary_key=True, autoincrement=True) hostname = Column(String(64), unique=True, nullable=False) ip_addr = Column(String(128), unique=True, nullable=False) port = Column(Integer, default=22) group = relationship('Group', secondary=HostToGroup.__table__, backref='host_list') # group =relationship("Group",back_populates='host_list') def __repr__(self): return "<id=%s,hostname=%s, ip_addr=%s>" % (self.id, self.hostname, self.ip_addr) class Group(Base): __tablename__ = 'group' id = Column(Integer, primary_key=True) name = Column(String(64), unique=True, nullable=False) def __repr__(self): return "<id=%s,name=%s>" % (self.id, self.name) Base.metadata.create_all(engine) # 创建所有表结构 if __name__ == '__main__': SessionCls = sessionmaker(bind=engine) session = SessionCls() # # g1 = Group(name='g1') # g2 = Group(name='g2') # g3 = Group(name='g3') # g4 = Group(name='g4') # session.add_all([g1,g2,g3,g4]) # h1 = Host(hostname='h1',ip_addr='192.168.1.56') # h2 = Host(hostname='h2',ip_addr='192.168.1.57',port=10000) # h3 = Host(hostname='ubuntu',ip_addr='192.168.1.58',port=10000) # # h1.group=[g2,g4] # session.add_all([h1,h2,h3]) # session.commit() # groups = session.query(Group).all() # h2 = session.query(Host).filter(Host.hostname=='h2').first() # h2.group = groups[:-1] # print("===========>",h2.group) g4 = session.query(Group).filter(Group.name=='g4').first() print(g4) obj1 = session.query(Host).filter(Host.hostname=='h1').update({'port':444}) obj2 = session.query(Host).filter(Host.hostname=='h1').first() # g4.host_list.append(obj2) obj2.group.append(g4) # # obj2= session.query(Host).filter(Host.hostname=='h1').first() # print("h1:",obj2.group) # print("g:",g4.host_list ) session.commit()