python操作数据库

• pip install PyMySQL

import pymysqlfrom pymysql.cursors import DictCursor# 1.创建连接(修高速公路)conn = pymysql.connect(    host='127.0.0.1',    user='admin',    password='12345',    port=3306,    db='mysql',    charset='utf8')# 2. 创建游标(运输车)# cursor = conn.cursor()  # 返回元组cursor = conn.cursor(DictCursor)  # 返回字典# 3. 执行sql(提货单)sql ="select count(1) total, (case when t1.status = 1 then '待整改' when t1.status = 2 then '待复查' when t1.status = 3 then '整改完成' else '未知类型' end) orderStatus from ibs_AI_iot.ai_rectification_main t1 left join ibs_ai_iot.work_order t3 on t1.id = t3.rectification_id where t1.project_id = 103672 and t1.delete_flag = 0 and t3.is_delete = 0 group by t1.status order by orderStatus desc;",res = cursor.execute(sql)print(res)# 4. 获取结果(卸货)res1 = cursor.fetchone() # 一次卸载一条res2 = cursor.fetchmany(3) # 一次卸载指定的条数res3 = cursor.fetchall() # 一次获取所有# 5. 关闭游标(车退掉)cursor.close()# 6. 关闭连接(路也断掉)conn.close()
[{'total': 30, 'orderStatus': '整改完成'}, {'total': 5, 'orderStatus': '待整改'}] 

import pymysqldb_config = {    'host': '127.0.0.1',    'user': 'admin',    'password': '123456',    'port': 3306,    'db': 'mysql',    'charset': 'utf8'}conn = pymysql.connect(**db_config)try:    with conn.cursor() as cursor: # 上下文管理--自动关闭游标        sql1 = 'UPDATE table t1  set t1.user_name="勇哥" where t1.username="h1" '        sql2 = 'UPDATE table t1  set t1.user_name="勇哥2" where t1.username="h2" '        cursor.execute(sql1)        cursor.execute(sql2)        # pymysql默认开启事务        conn.commit()except Exception as e:    # 回滚    conn.rollback()finally:    conn.close()