pymysql的使用與參數簡要

pymysql.Connect()參數說明
host(str):      MySQL服務器地址
port(int):      MySQL服務器端口號
user(str):      用戶名
passwd(str):    密碼
db(str):        數據庫名稱
charset(str):   連接編碼

connection對象支持的方法
cursor()        使用該連接創建並返回游標
commit()        提交當前事務
rollback()      回滾當前事務
close()         關閉連接

cursor對象支持的方法
execute(op)     執行一個數據庫的查詢命令
fetchone()      取得結果集的下一行
fetchmany(size) 獲取結果集的下幾行
fetchall()      獲取結果集中的所有行
rowcount()      返回數據條數或影響行數
close()         關閉游標對象

import pymysql.cursors

# 連接數據庫
connect = pymysql.Connect(
    host='localhost',
    port=3310,
    user='woider',
    passwd='3243',
    db='python',
    charset='utf8'
)

# 獲取游標
cursor = connect.cursor()

# 插入數據
sql = "INSERT INTO trade (name, account, saving) VALUES ( '%s', '%s', %.2f )"
data = ('雷軍', '13512345678', 10000)
cursor.execute(sql % data)
connect.commit()
print('成功插入', cursor.rowcount, '條數據')

# 修改數據
sql = "UPDATE trade SET saving = %.2f WHERE account = '%s' "
data = (8888, '13512345678')
cursor.execute(sql % data)
connect.commit()
print('成功修改', cursor.rowcount, '條數據')

# 查詢數據
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, '條數據')

# 刪除數據
sql = "DELETE FROM trade WHERE account = '%s' LIMIT %d"
data = ('13512345678', 1)
cursor.execute(sql % data)
connect.commit()
print('成功刪除', cursor.rowcount, '條數據')

# 事務處理
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)  # 儲蓄增加1000
    cursor.execute(sql_2)  # 支出增加1000
    cursor.execute(sql_3)  # 收入增加2000
except Exception as e:
    connect.rollback()  # 事務回滾
    print('事務處理失敗', e)
else:
    connect.commit()  # 事務提交
    print('事務處理成功', cursor.rowcount)

# 關閉連接
cursor.close()
connect.close()