Python操作MySQL主要使用两种方式：
下载安装
pip3 install pymysql
使用操作
1、执行SQL
1 # -*- coding:utf-8 -*- 2 3 import pymysql 4 5 # 创建连接 6 conn = pymysql.connect(host=‘127.0.0.1‘, port=3306, user=‘root‘, passwd=‘123‘, db=‘t1‘) 7 # 创建游标 8 cursor = conn.cursor() 9 10 # 执行SQL，并返回收影响行数 11 effect_row = cursor.execute("update hosts set host = ‘1.1.1.2‘") 12 13 # 执行SQL，并返回受影响行数 14 #effect_row = cursor.execute("update hosts set host = ‘1.1.1.2‘ where nid > %s", (1,)) 15 16 # 执行SQL，并返回受影响行数 17 #effect_row = cursor.executemany("insert into hosts(host,color_id)values(%s,%s)", [("1.1.1.11",1),("1.1.1.11",2)]) 18 19 20 # 提交，不然无法保存新建或者修改的数据 21 conn.commit() 22 23 # 关闭游标 24 cursor.close() 25 # 关闭连接 26 conn.close()
2、获取新创建数据自增ID
1 # -*- coding:utf-8 -*- 2 import pymysql 3 4 conn = pymysql.connect(host=‘127.0.0.1‘, port=3306, user=‘root‘, passwd=‘123‘, db=‘t1‘) 5 cursor = conn.cursor() 6 cursor.executemany("insert into hosts(host,color_id)values(%s,%s)", [("1.1.1.11",1),("1.1.1.11",2)]) 7 conn.commit() 8 cursor.close() 9 conn.close() 10 11 # 获取最新自增ID 12 new_id = cursor.lastrowid
3、获取查询数据
1 # -*- coding:utf-8 -*- 2 import pymysql 3 4 conn = pymysql.connect(host=‘127.0.0.1‘, port=3306, user=‘root‘, passwd=‘123‘, db=‘t1‘) 5 cursor = conn.cursor() 6 cursor.execute("select * from hosts") 7 8 # 获取第一行数据 9 row_1 = cursor.fetchone() 10 11 # 获取前n行数据 12 # row_2 = cursor.fetchmany(3) 13 # 获取所有数据 14 # row_3 = cursor.fetchall() 15 16 conn.commit() 17 cursor.close() 18 conn.close()
注：在fetch数据时按照顺序进行，可以使用cursor.scroll(num,mode)来移动游标位置，如：
4、fetch数据类型
关于默认获取的数据是元祖类型，如果想要或者字典类型的数据，即：
1 # -*- coding:utf-8 -*- 2 import pymysql 3 4 conn = pymysql.connect(host=‘127.0.0.1‘, port=3306, user=‘root‘, passwd=‘123‘, db=‘t1‘) 5 6 # 游标设置为字典类型 7 cursor = conn.cursor(cursor=pymysql.cursors.DictCursor) 8 r = cursor.execute("call p1()") 9 10 result = cursor.fetchone() 11 12 conn.commit() 13 cursor.close() 14 conn.close()
sqlachemy是Python编程语言下的一款ORM框架，该框架建立在数据库API之上，使用关系对象映射进行数据库操作，简言之便是：将对象转换成SQL，然后使用数据API执行SQL并获取执行结果。
安装：
pip3 install sqlachemy
sqlachemy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，如以pymsql为例：
mysql+pymysql://<username>:<password>@<host>/<dbname>[?<options>]
一、内部处理
使用 Engine/ConnectionPooling/Dialect 进行数据库操作，Engine使用ConnectionPooling连接数据库，然后再通过Dialect执行SQL语句。
1 # -*- coding:utf-8 -*- 2 from sqlalchemy import create_engine 3 4 5 engine = create_engine("mysql+pymysql://root:123@127.0.0.1:3306/t1", max_overflow=5) 6 7 # 执行SQL 8 # cur = engine.execute( 9 # "INSERT INTO hosts (host, color_id) VALUES (‘1.1.1.22‘, 3)" 10 # ) 11 12 # 新插入行自增ID 13 # cur.lastrowid 14 15 # 执行SQL 16 # cur = engine.execute( 17 # "INSERT INTO hosts (host, color_id) VALUES(%s, %s)",[(‘1.1.1.22‘, 3),(‘1.1.1.221‘, 3),] 18 # ) 19 20 21 # 执行SQL 22 # cur = engine.execute( 23 # "INSERT INTO hosts (host, color_id) VALUES (%(host)s, %(color_id)s)", 24 # host=‘1.1.1.99‘, color_id=3 25 # ) 26 27 # 执行SQL 28 # cur = engine.execute(‘select * from hosts‘) 29 # 获取第一行数据 30 # cur.fetchone() 31 # 获取第n行数据 32 # cur.fetchmany(3) 33 # 获取所有数据 34 # cur.fetchall()
二、ORM功能使用
使用 ORM/Schema Type/SQL Expression Language/Engine/ConnectionPooling/Dialect 所有组件对数据进行操作。根据类创建对象，对象转换成SQL，执行SQL。
1、创建表
表结构 + 数据库连接
1 # -*- coding:utf-8 -*- 2 from sqlalchemy.ext.declarative import declarative_base 3 from sqlalchemy import Column, Integer, String, ForeignKey, UniqueConstraint, Index 4 from sqlalchemy.orm import sessionmaker, relationship 5 from sqlalchemy import create_engine 6 7 engine = create_engine("mysql+pymysql://root:123@127.0.0.1:3306/t1", max_overflow=5) 8 9 Base = declarative_base() 10 11 # 创建单表 12 class Users(Base): 13 __tablename__ = ‘users‘ 14 id = Column(Integer, primary_key=True) 15 name = Column(String(32)) 16 extra = Column(String(16)) 17 18 __table_args__ = ( 19 UniqueConstraint(‘id‘, ‘name‘, name=‘uix_id_name‘), 20 Index(‘ix_id_name‘, ‘name‘, ‘extra‘), 21 ) 22 23 def __repr__(self): 24 return "%s-%s" %(self.id, self.name) 25 26 # 一对多 27 class Favor(Base): 28 __tablename__ = ‘favor‘ 29 nid = Column(Integer, primary_key=True) 30 caption = Column(String(50), default=‘red‘, unique=True) 31 32 def __repr__(self): 33 return "%s-%s" %(self.nid, self.caption) 34 35 class Person(Base): 36 __tablename__ = ‘person‘ 37 nid = Column(Integer, primary_key=True) 38 name = Column(String(32), index=True, nullable=True) 39 favor_id = Column(Integer, ForeignKey("favor.nid")) 40 # 与生成表结构无关，仅用于查询方便 41 favor = relationship("Favor", backref=‘pers‘) 42 43 # 多对多 44 class ServerToGroup(Base): 45 __tablename__ = ‘servertogroup‘ 46 nid = Column(Integer, primary_key=True, autoincrement=True) 47 server_id = Column(Integer, ForeignKey(‘server.id‘)) 48 group_id = Column(Integer, ForeignKey(‘group.id‘)) 49 group = relationship("Group", backref=‘s2g‘) 50 server = relationship("Server", backref=‘s2g‘) 51 52 class Group(Base): 53 __tablename__ = ‘group‘ 54 id = Column(Integer, primary_key=True) 55 name = Column(String(64), unique=True, nullable=False) 56 port = Column(Integer, default=22) 57 # group = relationship(‘Group‘,secondary=ServerToGroup,backref=‘host_list‘) 58 59 60 class Server(Base): 61 __tablename__ = ‘server‘ 62 63 id = Column(Integer, primary_key=True, autoincrement=True) 64 hostname = Column(String(64), unique=True, nullable=False) 65 66 67 68 69 def init_db(): 70 Base.metadata.create_all(engine) 71 72 73 def drop_db(): 74 Base.metadata.drop_all(engine) 75 76 77 Session = sessionmaker(bind=engine) 78 session = Session()
2、操作表
1 # -*- coding:utf-8 -*- 2 3 from sqlalchemy.ext.declarative import declarative_base 4 from sqlalchemy import Column, Integer, String 5 from sqlalchemy.orm import sessionmaker 6 from sqlalchemy import create_engine 7 8 engine = create_engine("mysql+mysqldb://root:123@127.0.0.1:3306/s11", max_overflow=5) 9 10 Base = declarative_base() 11 12 13 class User(Base): 14 __tablename__ = ‘users‘ 15 id = Column(Integer, primary_key=True) 16 name = Column(String(50)) 17 18 # 寻找Base的所有子类，按照子类的结构在数据库中生成对应的数据表信息 19 # Base.metadata.create_all(engine) 20 21 Session = sessionmaker(bind=engine) 22 session = Session() 23 24 25 # ########## 增 ########## 26 # u = User(id=2, name=‘sb‘) 27 # session.add(u) 28 # session.add_all([ 29 # User(id=3, name=‘sb‘), 30 # User(id=4, name=‘sb‘) 31 # ]) 32 # session.commit() 33 34 # ########## 删除 ########## 35 # session.query(User).filter(User.id > 2).delete() 36 # session.commit() 37 38 # ########## 修改 ########## 39 # session.query(User).filter(User.id > 2).update({‘cluster_id‘ : 0}) 40 # session.commit() 41 # ########## 查 ########## 42 # ret = session.query(User).filter_by(name=‘sb‘).first() 43 44 # ret = session.query(User).filter_by(name=‘sb‘).all() 45 # print ret 46 47 # ret = session.query(User).filter(User.name.in_([‘sb‘,‘bb‘])).all() 48 # print ret 49 50 # ret = session.query(User.name.label(‘name_label‘)).all() 51 # print ret,type(ret) 52 53 # ret = session.query(User).order_by(User.id).all() 54 # print ret 55 56 # ret = session.query(User).order_by(User.id)[1:3] 57 # print ret 58 # session.commit()
# -*- coding:utf-8 -*-from sqlalchemy.ext.declarative import declarative_basefrom sqlalchemy import Column, Integer, Stringfrom sqlalchemy.orm import sessionmakerfrom sqlalchemy import create_engineengine = create_engine("mysql+mysqldb://root:123@127.0.0.1:3306/s11", max_overflow=5)Base = declarative_base()class User(Base): __tablename__ = ‘users‘ id = Column(Integer, primary_key=True) name = Column(String(50))# 寻找Base的所有子类，按照子类的结构在数据库中生成对应的数据表信息# Base.metadata.create_all(engine)Session = sessionmaker(bind=engine)session = Session()# ########## 增 ########### u = User(id=2, name=‘sb‘)# session.add(u)# session.add_all([# User(id=3, name=‘sb‘),# User(id=4, name=‘sb‘)# ])# session.commit()# ########## 删除 ########### session.query(User).filter(User.id > 2).delete()# session.commit()# ########## 修改 ########### session.query(User).filter(User.id > 2).update({‘cluster_id‘ : 0})# session.commit()# ########## 查 ########### ret = session.query(User).filter_by(name=‘sb‘).first()# ret = session.query(User).filter_by(name=‘sb‘).all()# print ret# ret = session.query(User).filter(User.name.in_([‘sb‘,‘bb‘])).all()# print ret# ret = session.query(User.name.label(‘name_label‘)).all()# print ret,type(ret)# ret = session.query(User).order_by(User.id).all()# print ret# ret = session.query(User).order_by(User.id)[1:3]# print ret# session.commit()Python3 之 MySQL操作模块：pymsql和sqlachemy
原文：http://www.cnblogs.com/JayeHe/p/7518222.html