如何从 mysql 通过 python 提取的数据中提取 plot 图形？

Question

import mysql.connector as myc
from mysql.connector import Error
import matplotlib.pyplot as plt
import pandas as pd

db = myc.connect(host='localhost',database='patients',user='root',password='root')
mc = db.cursor()
mc.execute('select count(*) from corona group by date')
for i in mc:
    x=[]
    x=x.append(i)
mc.execute('select distinct date from corona ')
for j in mc:
    y=[]
    y=y.append(j)
    
plt.plot([x],[y])
plt.legend()
plt.show()

this is the code we are using here for plotting a line graph. what we are expecting is that the graph should show distinct dates in ascending order. we wanted to plot a graph with the no.of patients that have entered that day versus the date. we wanted to show a gradual increase or decrease in the count. but this code does not show that (the image attached) and no error is also shown. we can't find what is wrong also. please help. I would really appreciate any answer but with a little minimum explanation.

enter image description here

Answer 1

An empty plot can happen when your x and y have length 1. You can use plt.plot([x],[y], '.') to confirm. This would plot the data as points