pymysql学习笔记

import pymysql.cursors

db = pymysql.Connect(
host='localhost',
port=3306,
user='root',
passwd='root',
db='mydb',
charset="utf8"
)

cursor = db.cursor()

sql = "INSERT INTO trade (name, account, saving) VALUES ( '%s', '%s', %.2f )"
data = ('雷军', '13512345678', 10000)
cursor.execute(sql % data)
db.commit()
print('成功插入', cursor.rowcount, '条数据')

sql = "UPDATE trade SET saving = %.2f WHERE account = '%s' "
data = (8888, '13512345678')
cursor.execute(sql % data)
db.commit()
print('成功修改', cursor.rowcount, '条数据')

sql = "SELECT name,saving FROM trade WHERE account = '%s' "
data = ('13512345678',)
cursor.execute(sql % data)
for row in cursor.fetchall():
    print("Name:%s\tSaving:%.2f" % row)
print('共查找出', cursor.rowcount, '条数据')

sql = "DELETE FROM trade WHERE account = '%s' LIMIT %d"
data = ('13512345678', 1)
cursor.execute(sql % data)
db.commit()
print('成功删除', cursor.rowcount, '条数据')

sql_1 = "UPDATE trade SET saving = saving + 1000 WHERE account = '18012345678' "
sql_2 = "UPDATE trade SET expend = expend + 1000 WHERE account = '18012345678' "
sql_3 = "UPDATE trade SET income = income + 2000 WHERE account = '18012345678' "

try:
    cursor.execute(sql_1)  # 储蓄增加1000
    cursor.execute(sql_2)  # 支出增加1000
    cursor.execute(sql_3)  # 收入增加2000
except Exception as e:
    db.rollback()  # 事务回滚
    print('事务处理失败', e)
else:
    db.commit()  # 事务提交
    print('事务处理成功', cursor.rowcount)

cursor.close()
db.close()