MySQL— pymysql and SQLAlchemy

#在终端直接运行
pip3 install pymysql

#!/usr/bin/env python# -*- coding:utf-8 -*-import pymysql
  # 创建连接conn = pymysql.connect(host='127.0.0.1', port=3306, user='root', passwd='123', db='t1')# 创建游标cursor = conn.cursor()
  # 执行SQL，并返回受影响行数effect_row = cursor.execute("update hosts set host = '1.1.1.2'")
  # 执行SQL，并返回受影响行数#effect_row = cursor.execute("update hosts set host = '1.1.1.2' where nid > %s", (1,))  # 执行SQL，并返回受影响行数#effect_row = cursor.executemany("insert into hosts(host,color_id)values(%s,%s)", [("1.1.1.11",1),("1.1.1.11",2)])  
  # 提交，不然无法保存新建或者修改的数据conn.commit()
  # 关闭游标cursor.close()# 关闭连接conn.close()

#!/usr/bin/env python# -*- coding:utf-8 -*-import pymysql
  
conn = pymysql.connect(host='127.0.0.1', port=3306, user='root', passwd='123', db='t1')
cursor = conn.cursor()
cursor.executemany("insert into hosts(host,color_id)values(%s,%s)", [("1.1.1.11",1),("1.1.1.11",2)])
conn.commit()# 获取最新自增IDnew_id = cursor.lastrowid

cursor.close()
conn.close()

#!/usr/bin/env python# -*- coding:utf-8 -*-import pymysql
  
conn = pymysql.connect(host='127.0.0.1', port=3306, user='root', passwd='123', db='t1')
cursor = conn.cursor()
cursor.execute("select * from hosts")
  # 获取第一行数据row_1 = cursor.fetchone()
  # 获取前n行数据# row_2 = cursor.fetchmany(3)# 获取所有数据# row_3 = cursor.fetchall()  
conn.commit()
cursor.close()
conn.close()

#!/usr/bin/env python# -*- coding:utf-8 -*-import pymysql
  
conn = pymysql.connect(host='127.0.0.1', port=3306, user='root', passwd='123', db='t1')
  # 游标设置为字典类型cursor = conn.cursor(cursor=pymysql.cursors.DictCursor)
r = cursor.execute("call p1()")
  
result = cursor.fetchone()
  
conn.commit()
cursor.close()
conn.close()

#在终端直接运行pip3 install SQLAlchemy

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()

#　条件ret = session.query(Users).filter_by(name='alex').all()    # 条件内为关键字表达式ret = session.query(Users).filter(Users.id > 1, Users.name == 'eric').all()    # 条件内为SQL表达式ret = session.query(Users).filter(Users.id.between(1, 3), Users.name == 'eric').all()    # betweenret = session.query(Users).filter(Users.id.in_([1,3,4])).all()    # inret = session.query(Users).filter(~Users.id.in_([1,3,4])).all()    # not inret = session.query(Users).filter(Users.id.in_(session.query(Users.id).filter_by(name='eric'))).all()    # 子查询条件from sqlalchemy import and_, or_
ret = session.query(Users).filter(and_(Users.id > 3, Users.name == 'eric')).all()    # andret = session.query(Users).filter(or_(Users.id < 2, Users.name == 'eric')).all()    # orret = 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()    # e开头ret = session.query(Users).filter(~Users.name.like('e%')).all()    # 非e开头# 限制ret = session.query(Users)[1:2]    # 相当于limit# 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()    # 笛卡儿积连表ret = session.query(Person).join(Favor).all()    # 默认内连 inner joinret = session.query(Person).join(Favor, isouter=True).all()    # 左连# 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()