pymysql transaction

# 导包
import pymysql
# 捕获异常
conn,cursor = None, None # 提前定义变量，防止出现异常之后，没有变量的问题
try :
# 建立连接
conn = pymysql.connect(host="localhost", user="root", password="root",
database="books", port=3306, charset="utf8")
# 获取游标
cursor = conn.cursor()
# 先执行插入三体这本书的操作
cursor.execute("insert into t_book(`id`,`title`,`pub_date`) values(11, '三体', '1970-01-01');")
# 再执行插入逻辑人物的操作
cursor.execute("insert into t_hero(id, `name`,`gender`,`book_id`) values('逻辑11111', 1, 4);")
# 提交事务
conn.commit()
print("提交事务成功")
except Exception as e:
# 回滚事务
cursor.execute("select * from t_book;")
print("回滚之前书中有哪些数据：",cursor.fetchall())
cursor.execute("select * from t_hero;")
print("回滚之前英雄人物中有哪些数据：", cursor.fetchall())

conn.rollback() # 回滚

cursor.execute("select * from t_book;")
print("回滚之后书中有哪些数据：",cursor.fetchall())
cursor.execute("select * from t_hero;")
print("回滚只会英雄人物中有哪些数据：", cursor.fetchall())
print("回滚事务成功")

finally:
# 关闭游标和关闭连接
cursor.close()
conn.close()