from sqlalchemy import (BigInteger, Column, DateTime, Integer, MetaData,
String, Table, create_engine, text)
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import mapper
from sqlalchemy.schema import CreateTable
# 本地数据库
engineLocal = create_engine('mysql+pymysql://root:root@127.0.0.1:3306/lingyun?charset=utf8')
Base = declarative_base()
metadata = MetaData()
def dictToObj(results, to_class):
"""将字典list或者字典转化为指定类的对象list或指定类的对象
python 支持动态给对象添加属性，所以字典中存在而该类不存在的会直接添加到对应对象
if isinstance(results, list):
objL = []
for result in results:
obj = to_class()
for r in result.keys():
obj.__setattr__(r, result[r])
objL.append(obj)
return objL
else:
obj = to_class()
for r in results.keys():
obj.__setattr__(r, results[r])
return obj
except Exception as e:
print(e)
traceback.print_exc()
return None
# else:
# print("传入对象非字典或者list")
# return None
def getModel(name, engine):
"""根据name创建并return一个新的model类
name:数据库表名
engine:create_engine返回的对象，指定要操作的数据库连接，from sqlalchemy import create_engine
Base.metadata.reflect(engine)
table = Base.metadata.tables[name]
t = type(name,(object,),dict())
mapper(t, table)
Base.metadata.clear()
return t
def createTableFromTable(name, tableNam, engine):
"""copy一个已有表的结构，并创建新的表
metadata = MetaData(engine)
Base.metadata.reflect(engine)
# 获取原表对象
table = Base.metadata.tables[tableNam]
# 获取原表建表语句
c = str(CreateTable(table))
# 替换表名
c = c.replace("CREATE TABLE " + tableNam, "CREATE TABLE if not exists " + name)
db_conn = engine.connect()
db_conn.execute(c)
db_conn.close()
Base.metadata.clear()
def getNewModel(name, tableNam, engine):
"""copy一个表的表结构并创建新的名为name的表并返回model类
name:数据库表名
tableNam:copy的表表名
engine:create_engine返回的对象，指定要操作的数据库连接，from sqlalchemy import create_engine
createTableFromTable(name, tableNam, engine)
return getModel(name, engine)
https://blog.csdn.net/j_object/article/details/80118657
