参考文档

Flask-SQLAlchemy

Flask-Script

Flask-Migrate

Celery

Sanic官方文档

一.执行原生SQL语句

1.实例一

import time
import threading
import sqlalchemy
from sqlalchemy import create_engine
from sqlalchemy.engine.base import Engine engine = create_engine(
"mysql+pymysql://root:123@127.0.0.1:3306/t1?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)
) def task(arg):
conn = engine.raw_connection()
cursor = conn.cursor()
cursor.execute(
"select * from t1"
)
result = cursor.fetchall()
cursor.close()
conn.close() for i in range(20):
t = threading.Thread(target=task, args=(i,))
t.start()

2.实例二

import time
import threading
import sqlalchemy
from sqlalchemy import create_engine
from sqlalchemy.engine.base import Engine engine = create_engine("mysql+pymysql://root:123@127.0.0.1:3306/t1", max_overflow=0, pool_size=5) def task(arg):
conn = engine.contextual_connect()
with conn:
cur = conn.execute(
"select * from t1"
)
result = cur.fetchall()
print(result) for i in range(20):
t = threading.Thread(target=task, args=(i,))
t.start()

2.实例三

import time
import threading
import sqlalchemy
from sqlalchemy import create_engine
from sqlalchemy.engine.base import Engine
from sqlalchemy.engine.result import ResultProxy
engine = create_engine("mysql+pymysql://root:123@127.0.0.1:3306/t1", max_overflow=0, pool_size=5) def task(arg):
cur = engine.execute("select * from t1")
result = cur.fetchall()
cur.close()
print(result) for i in range(20):
t = threading.Thread(target=task, args=(i,))
t.start()

二.ORM操作

1.创建数据库表

(1)创建单表

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 Base = declarative_base() class Users(Base):
__tablename__ = 'users' id = Column(Integer, primary_key=True)
name = Column(String(32), index=True, nullable=False)
# 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', 'email'),
) def init_db():
"""
根据类创建数据库表
:return:
"""
engine = create_engine(
"mysql+pymysql://root:123@127.0.0.1:3306/s6?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:123@127.0.0.1:3306/s6?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()

(2)创建多个表并包含FK、M2M关系

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:123@127.0.0.1:3306/s6?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:123@127.0.0.1:3306/s6?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()

2.操作数据库表

from sqlalchemy.orm import sessionmaker
from sqlalchemy import create_engine
from models import Users engine = create_engine("mysql+pymysql://root:123@127.0.0.1:3306/s6", max_overflow=0, pool_size=5)
Session = sessionmaker(bind=engine) # 每次执行数据库操作时,都需要创建一个session
session = Session() # ############# 执行ORM操作 #############
obj1 = Users(name="alex1")
session.add(obj1) # 提交事务
session.commit()
# 关闭session
session.close()

(1)基于scoped_session实现线程安全

from sqlalchemy.orm import sessionmaker
from sqlalchemy import create_engine
from sqlalchemy.orm import scoped_session
from models import Users engine = create_engine("mysql+pymysql://root:123@127.0.0.1:3306/s6", max_overflow=0, pool_size=5)
Session = sessionmaker(bind=engine) """
# 线程安全,基于本地线程实现每个线程用同一个session
# 特殊的:scoped_session中有原来方法的Session中的一下方法: public_methods = (
'__contains__', '__iter__', 'add', 'add_all', 'begin', 'begin_nested',
'close', 'commit', 'connection', 'delete', 'execute', 'expire',
'expire_all', 'expunge', 'expunge_all', 'flush', 'get_bind',
'is_modified', 'bulk_save_objects', 'bulk_insert_mappings',
'bulk_update_mappings',
'merge', 'query', 'refresh', 'rollback',
'scalar'
)
"""
session = scoped_session(Session) # ############# 执行ORM操作 #############
obj1 = Users(name="alex1")
session.add(obj1) # 提交事务
session.commit()
# 关闭session
session.close()

(2)多线程执行示例

import time
import threading 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
from db import Users engine = create_engine("mysql+pymysql://root:123@127.0.0.1:3306/s6", max_overflow=0, pool_size=5)
Session = sessionmaker(bind=engine) def task(arg):
session = Session() obj1 = Users(name="alex1")
session.add(obj1) session.commit() for i in range(10):
t = threading.Thread(target=task, args=(i,))
t.start()

(3)基本增删改查示例

import time
import threading 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
from sqlalchemy.sql import text from db import Users, Hosts engine = create_engine("mysql+pymysql://root:123@127.0.0.1:3306/s6", max_overflow=0, pool_size=5)
Session = sessionmaker(bind=engine) session = Session() # ################ 添加 ################
"""
obj1 = Users(name="wupeiqi")
session.add(obj1) session.add_all([
Users(name="wupeiqi"),
Users(name="alex"),
Hosts(name="c1.com"),
])
session.commit()
""" # ################ 删除 ################
"""
session.query(Users).filter(Users.id > 2).delete()
session.commit()
"""
# ################ 修改 ################
"""
session.query(Users).filter(Users.id > 0).update({"name" : "099"})
session.query(Users).filter(Users.id > 0).update({Users.name: Users.name + "099"}, synchronize_session=False)
session.query(Users).filter(Users.id > 0).update({"age": Users.age + 1}, synchronize_session="evaluate")
session.commit()
"""
# ################ 查询 ################
"""
r1 = session.query(Users).all()
r2 = session.query(Users.name.label('xx'), Users.age).all()
r3 = session.query(Users).filter(Users.name == "alex").all()
r4 = session.query(Users).filter_by(name='alex').all()
r5 = session.query(Users).filter_by(name='alex').first()
r6 = session.query(Users).filter(text("id<:value and name=:name")).params(value=224, name='fred').order_by(Users.id).all()
r7 = session.query(Users).from_statement(text("SELECT * FROM users where name=:name")).params(name='ed').all()
""" session.close()

(4)常用操作

# 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()

(5)原生SQL语句

import time
import threading 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
from sqlalchemy.sql import text
from sqlalchemy.engine.result import ResultProxy
from db import Users, Hosts engine = create_engine("mysql+pymysql://root:123@127.0.0.1:3306/s6", max_overflow=0, pool_size=5)
Session = sessionmaker(bind=engine) session = Session() # 查询
# cursor = session.execute('select * from users')
# result = cursor.fetchall() # 添加
cursor = session.execute('insert into users(name) values(:value)',params={"value":'wupeiqi'})
session.commit()
print(cursor.lastrowid) session.close()

(6)基于relationship操作ForeignKey

import time
import threading 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
from sqlalchemy.sql import text
from sqlalchemy.engine.result import ResultProxy
from db import Users, Hosts, Hobby, Person engine = create_engine("mysql+pymysql://root:123@127.0.0.1:3306/s6?charset=utf8", max_overflow=0, pool_size=5)
Session = sessionmaker(bind=engine)
session = Session() # 添加
"""
session.add_all([
Hobby(caption='乒乓球'),
Hobby(caption='羽毛球'),
Person(name='张三', hobby_id=3),
Person(name='李四', hobby_id=4),
]) person = Person(name='张九', hobby=Hobby(caption='姑娘'))
session.add(person) hb = Hobby(caption='人妖')
hb.pers = [Person(name='文飞'), Person(name='博雅')]
session.add(hb) session.commit()
""" # 使用relationship正向查询
"""
v = session.query(Person).first()
print(v.name)
print(v.hobby.caption)
""" # 使用relationship反向查询
"""
v = session.query(Hobby).first()
print(v.caption)
print(v.pers)
""" session.close()

(7)基于relationship操作m2m

import time
import threading 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
from sqlalchemy.sql import text
from sqlalchemy.engine.result import ResultProxy
from db import Users, Hosts, Hobby, Person, Group, Server, Server2Group engine = create_engine("mysql+pymysql://root:123@127.0.0.1:3306/s6?charset=utf8", max_overflow=0, pool_size=5)
Session = sessionmaker(bind=engine)
session = Session()
# 添加
"""
session.add_all([
Server(hostname='c1.com'),
Server(hostname='c2.com'),
Group(name='A组'),
Group(name='B组'),
])
session.commit() s2g = Server2Group(server_id=1, group_id=1)
session.add(s2g)
session.commit() gp = Group(name='C组')
gp.servers = [Server(hostname='c3.com'),Server(hostname='c4.com')]
session.add(gp)
session.commit() ser = Server(hostname='c6.com')
ser.groups = [Group(name='F组'),Group(name='G组')]
session.add(ser)
session.commit()
""" # 使用relationship正向查询
"""
v = session.query(Group).first()
print(v.name)
print(v.servers)
""" # 使用relationship反向查询
"""
v = session.query(Server).first()
print(v.hostname)
print(v.groups)
""" session.close()

(8)其他

import time
import threading 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
from sqlalchemy.sql import text, func
from sqlalchemy.engine.result import ResultProxy
from db import Users, Hosts, Hobby, Person, Group, Server, Server2Group engine = create_engine("mysql+pymysql://root:123@127.0.0.1:3306/s6?charset=utf8", max_overflow=0, pool_size=5)
Session = sessionmaker(bind=engine)
session = Session() # 关联子查询
subqry = session.query(func.count(Server.id).label("sid")).filter(Server.id == Group.id).correlate(Group).as_scalar()
result = session.query(Group.name, subqry)
"""
SELECT `group`.name AS group_name, (SELECT count(server.id) AS sid
FROM server
WHERE server.id = `group`.id) AS anon_1
FROM `group`
""" # 原生SQL
"""
# 查询
cursor = session.execute('select * from users')
result = cursor.fetchall() # 添加
cursor = session.execute('insert into users(name) values(:value)',params={"value":'wupeiqi'})
session.commit()
print(cursor.lastrowid)
""" session.close()

SQLAlchemy相关文档的更多相关文章

  1. 20190131 经验总结:如何从rst文件编译出自己的sqlalchemy的文档

    20190131 经验总结:如何编译sqlalchemy的文档 起因 www.sqlalchemy.org官网上不去了,不管是直接上,还是用代理都不行. sqlalchemy属于常用工具,看不到官方的 ...

  2. dotNET跨平台相关文档整理

    一直在从事C#开发的相关技术工作,从C# 1.0一路用到现在的C# 6.0, 通常情况下被局限于Windows平台,Mono项目把我们C#程序带到了Windows之外的平台,在工作之余花了很多时间在M ...

  3. Mybatis-Generator 自动生成Dao、Model、Mapping相关文档

    最近在学习mybatis,结果在写Mapping的映射文件时insert语句一直报错,于是想看看标准的映射文件是什么样.百度到Mybatis-Generator 自动生成Dao.Model.Mappi ...

  4. VLC的相关文档以及javascript接口

    参看下面链接:VLC相关文档

  5. dotNET跨平台相关文档

    dotNET跨平台相关文档整理 一直在从事C#开发的相关技术工作,从C# 1.0一路用到现在的C# 6.0, 通常情况下被局限于Windows平台,Mono项目把我们C#程序带到了Windows之外的 ...

  6. 大数据相关文档&Api下载

    IT相关文档&Api下载(不断更新中) 下载地址:https://download.csdn.net/user/qq_42797237/uploads 如有没有你需要的API,可和我留言,留下 ...

  7. rn相关文档

    RN相关文档: rn文档:https://reactnative.cn/ mbox文档:https://cn.mobx.js.org/ es6文档:http://es6.ruanyifeng.com/ ...

  8. OSS阿里云相关文档

    OSS阿里云相关文档 oss文档链接

  9. hugo官方相关文档地址

    +++ date="2020-10-17" title="hugo官方相关文档地址" tags=["hugo"] categories=[& ...

随机推荐

  1. 46、[源码]-Spring容器创建-注册BeanPostProcessors

    46.[源码]-Spring容器创建-注册BeanPostProcessors 6.registerBeanPostProcessors(beanFactory);注册BeanPostProcesso ...

  2. xlrd/xlwt

    操作 xls格式的excel文件 读模块 xlrd import xlrd 打开文件 wb= xlrd.open_workbook('xxxx.xls') 获取excel中的表 ws= wb.shee ...

  3. css选择器:first-child与:first-of-type的区别

    :first-child选择器是css2中定义的选择器,从字面意思上来看也很好理解,就是第一个子元素.比如有段代码: <div> <p>第一个子元素</p> < ...

  4. decodeURI 与 decodeURIComponent 区别

    1. 关于URL.encodeURI 及 encodeURIComponent: URI: Uniform Resource Identifiers,通用资源标识符 Global 对象的 encode ...

  5. loj #2316

    最短路 + 记忆化 记忆化搜索更容易实现 #include <iostream> #include <cstdio> #include <algorithm> #i ...

  6. PHP全栈学习笔记25

    <?php /* *@Author: 达叔小生 **/ header("content-type:image/png"); //设置页面编码 $num = $_GET['nu ...

  7. 01.Flink笔记-编译、部署

    Flink开发环境部署配置 Flink是一个以Java及Scala作为开发语言的开源大数据项目,代码开源在github上,并使用maven来编译和构建项目.所需工具:Java.maven.Git. 本 ...

  8. VTK 简单点云数据显示绘制

    基于vtkPolyData,绘制时除了输入点坐标,还需要通过setVerts指定点绘制信息. simplePoints.txt的内容为简单的 xyz,如: 20 20 20 20 20 30 20 2 ...

  9. 1829:【02NOIP提高组】自由落体

    #include<bits/stdc++.h> using namespace std; double h,s1,v,k,l; int n,ans; int main() { cin> ...

  10. springboot开启gzip压缩

    springboot 2.x开启gzip压缩 1.application.yml配置 server: compression: enabled: true min-response-size: mim ...