Question

我需要从MySQL工作台获取一些数据到Python中，这样我才能制作图表。但是当我尝试插入它并尝试打印值时，这是使用pymysql（参见代码）。它运行得很慢。

所以我想当我在做实时图表和更多东西时，程序会冻结......

有人有解决方案吗？

我的代码：

import pymysql

conn= pymysql.connect(host='127.0.0.1',
                      port= 3306,
                      user= 'root',
                      passwd= '******',
                      db= 'energie'
                      )
a = conn.cursor()

sql1 = 'SELECT `VarValue`, `VarName` from `gasmeter1`;'
a.execute(sql1)

gasmeter1 = a.fetchone()

sql2 = 'SELECT `VarValue` from `gasmeter2`;'
a.execute(sql2)

gasmeter2 = a.fetchone()

sql3 = 'SELECT `VarValue` from `gasmeter349`;'
a.execute(sql3)

gasmeter349 = a.fetchone()

sql4 = 'SELECT `VarValue` from `binnentemp ahu3010`;'
a.execute(sql4)

Binnentemperatuur = a.fetchone()

sql5 = 'SELECT `VarValue` from `buiten temp241`;'
a.execute(sql5)

Buitentemperatuur = a.fetchone()

print (gasmeter1[0] , gasmeter2[0] , gasmeter349[0] , Buitentemperatuur[0] , Binnentemperatuur[0])

这只是一个简单的代码，但速度很慢。有人建议吗？

时间：

代码：

import pymysql
import time

conn= pymysql.connect(host='127.0.0.1',
                    port= 3306,
                    user= 'root',
                    passwd= 'ohdecg',
                    db= 'energie'
                     )

a = conn.cursor()

t1 = time.time()

sql1 = 'SELECT `VarValue` from `gasmeter1`;'
a.execute(sql1)

gasmeter1 = a.fetchone ()

sql2 = 'SELECT `VarValue` from `gasmeter2`;'
a.execute(sql2)

gasmeter2 = a.fetchone ()

sql3 = 'SELECT `VarValue` from `gasmeter349`;'
a.execute(sql3)

gasmeter349 = a.fetchone ()

sql4 = 'SELECT `VarValue` from `binnentemp ahu3010`;'
a.execute(sql4)

Binnentemperatuur = a.fetchone()

sql5 = 'SELECT `VarValue` from `buiten temp241`;'
a.execute(sql5)

Buitentemperatuur = a.fetchone()

t2 = time.time()
print("The SQL statement took : {} s".format(t2 - t1))
#print (gasmeter1[0] , gasmeter2[0], gasmeter349[0])

>>> 
========================= RESTART: C:\Python27\j.py =========================
The SQL statement took : 32.0269999504 s
>>>

Answer 1

你的桌子有多大？你每次都要检索整个表，然后只取第一个元素。你可以尝试用这样的东西计时：

import time
...

t1 = time.time()
sql4 = 'SELECT `VarValue` from `binnentemp ahu3010`;'
a.execute(sql4)
t2 = time.time()
print("The SQL statement took : {} s".format(t2 - t1))

获取数据MySQL非常慢

1 个答案: