如果对于sqlalchemy框架不会使用，可以看——Python操作MySql——使用SQLAlchemy ORM操作数据库
1 使用sqlalchemy 框架，连接数据库
from random import random
from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import Column, Integer, String
from sqlalchemy.orm import sessionmaker
from sqlalchemy.pool import NullPool
#创建连接对象也就是为了连接到本地的数据库
engine = create_engine('mysql+pymysql://root:root@localhost:3306/testdab',
encoding='utf-8', # 编码格式
echo=True, # 是否开启sql执行语句的日志输出
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） （默认为-1）,其实session并不会被close
poolclass=NullPool # 无限制连接数
)
#声名Base
Base = declarative_base()
# 创建会话
session = sessionmaker(engine)
mySession = session()
2 创建类，与连接的数据库的字段相互映射
class User(Base):
__tablename__ = 'grade'
id = Column(Integer, primary_key=True, autoincrement=True)
name = Column(String(64), nullable=False)
Cgrade = Column(Integer, nullable=False)
Mgrade = Column(Integer, nullable=False)
Egrade = Column(Integer, nullable=False)
__table_args__ = {
"mysql_charset": "utf8"
}
3 批量插入数据100条
for i in range(1,100):
user = User(id = i,name="小红",Cgrade = int(random()*100),Egrade = int(random()*100),Mgrade = int(random()*100))
mySession.add(user)
mySession.commit()
4 批量修改数据
for i in range(1,100):
result = mySession.query(User).filter(User.id == i).first()
Cgrade = result.Cgrade + 5
sql = "update grade set Cgrade = %s where id = %s"
engine.execute(sql,(Cgrade,i))
5 批量删除数据（根据id）
for i in range(1,100):
mySession.query(User).filter(User.id == i).delete()
mySession.commit()
6 批量查询数据
for i in range(1,50):
sql = "select name,Cgrade from grade where id = %s"
result = engine.execute(sql,i)
print(result.fetchall())
7 完整代码
from random import random
from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy import Column, Integer, String
from sqlalchemy.orm import sessionmaker
from sqlalchemy.pool import NullPool
#创建连接对象也就是为了连接到本地的数据库
engine = create_engine('mysql+pymysql://root:root@localhost:3306/testdab',
encoding='utf-8', # 编码格式
echo=True, # 是否开启sql执行语句的日志输出
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） （默认为-1）,其实session并不会被close
poolclass=NullPool # 无限制连接数
)
#声名Base
Base = declarative_base()
# 创建会话
session = sessionmaker(engine)
mySession = session()
# 创建类，继承基类，用基本类型描述数据库结构
class User(Base):
__tablename__ = 'grade'
id = Column(Integer, primary_key=True, autoincrement=True)
name = Column(String(64), nullable=False)
Cgrade = Column(Integer, nullable=False)
Mgrade = Column(Integer, nullable=False)
Egrade = Column(Integer, nullable=False)
__table_args__ = {
"mysql_charset": "utf8"
}
# 插入100条数据
#for i in range(1,100):
# user = User(id = i,name="小红",Cgrade = int(random()*100),Egrade = int(random()*100),Mgrade = int(random()*100))
# mySession.add(user)
#mySession.commit()
#批量更改数据
#for i in range(1,100):
# result = mySession.query(User).filter(User.id == i).first()
# Cgrade = result.Cgrade + 5
# sql = "update grade set Cgrade = %s where id = %s"
# engine.execute(sql,(Cgrade,i))
for i in range(1,50):
sql = "select name,Cgrade from grade where id = %s"
result = engine.execute(sql,i)
print(result.fetchall())
#根据id批量删除数据
#for i in range(1,100):
# mySession.query(User).filter(User.id == i).delete()
#mySession.commit()
#sql语句查询
#result = engine.execute("select * from grade")
#print(result.fetchall())
