如何将 MySQL 记录值查询到 Python 变量？

Question

我想为 python 变量提供我从 MySQL 数据库中获取的值。

#!/usr/bin/python -u
# -*- coding: UTF-8 -*-

import time
import datetime
import mysql.connector
import sys

db = mysql.connector.connect(
    host = "localhost",
    user = "admin",
    password = "admin",
    db = "testonly"
)
mycursor = db.cursor()

if __name__ == '__main__':
    temp = 0
    mycursor.execute("SELECT temperature FROM table ORDER BY primarykey DESC LIMIT 1;") #By selecting one column in a row, I fetch only one record from the talbe.
    data = mycursor.fetchone()
    for temperature in data:
        print(temperature)

    temp = data['temperature']

    sys.exit() 

然后我有这样的错误：

File "test.py", line 28, in <module>
    temp = data['temperature']
TypeError: tuple indices must be integers, not str

我可以通过哪种方式为 python 变量赋值以供以后使用？

Answer 1

默认情况下，fetchone 返回一个包含数据库数据的元组。就目前而言，您需要按索引访问数据

temp = data[0]

如果您想通过temperature 键访问您的数据，您需要使用指定您的光标

from mysql.connector.cursor import MySQLCursorDict
...

mycursor = db.cursor(cursor_class=MySQLCursorDict)

...

temp = data['temperature']

Answer 2

您的对象data 是一个元组，不能这样引用。你需要使用这个：

temp = data[0]