如何使用 mysql.connector 流式传输结果

Question

自从大学时代以来，我对 sql 和 python 已经很生疏了。

我想知道如何逐行读取查询结果而不是fetchall？

这是我当前的测试代码：

#!/usr/bin/python
import time
import csv
import mysql.connector

start_time = time.time()
cnx = mysql.connector.connect(user='user', password='1234',
                              host='10.0.10.100',
                              database='serverDB')

try:
 cursor = cnx.cursor()   
 cursor.execute("select * from serverDB.task")
 result = cursor.fetchall()
 with open("query.csv", "wb") as csv_file:
    csv_writer = csv.writer(csv_file)
    csv_writer.writerow([i[0] for i in cursor.description]) # write headers
    csv_writer.writerows(result)

 for x, row in enumerate(result):
  print x
  print row
  #print result
finally:
 cnx.close()
 print "there are ", numrows, "rows"
 print("--- %s seconds ---" % (time.time() - start_time))

Answer 1

有一个函数叫做fetchone。该函数的用法如下：

connect = MySQLdb.connect(......)
cursor = connect.cursor()
cursor.execute('select......')
row_count = cursor.rowcount

for i in range(row_count):
    line = cursor.fetchone()    #you can operate each line