问用Python应用程序连接Oracle DB绘制图形

EN

import cx_Oracle
import matplotlib.pyplot as plt


query = 'SELECT order_date, count(order_id) order_count
     FROM orders WHERE order_date BETWEEN ' + st_date + ' AND ' + end_date +
         ' GROUP BY order_date '

order_date =  []
order_count = []


#connect to database and execute query.
db = cx_Oracle.connect('user', 'password', 'localhost:1521/XE')
cursor = db.cursor()
cursor.execute(query)

#loop through the rows fetched and store the records as arrays.
for row in cursor:
    order_date.append(row[0])
    order_count.append(row[1])

#plot the bar chart

plt.bar(order_date,order_count)