使用 python 在 SQL 服务器中快速插入数据

Question

I want to insert data from a CSV file into SQL Server database hosted on Azure. I was able to insert data in the table by reading the data into a pandas dataframe and using insert statement in a for loop in python. I am using pyodbc . This approach took a long time for the data to get inserted. I also tried pd.to_sql() . Though the later is faster than for loop approach, it is still slow.

Is there any faster way to insert CSV file in SQL Server using python/pandas?

Answer 1

Use threads so each one can insert into the db. A good example is provided by this guy who has a great example. Check this link .

Take a look at this part of the code where he starts the threads that point to the insert function.

def rnd_user(num=1000001, threadid=1):
  query = u"INSERT INTO imdb.employees (fname, lname, hired, job_code, store_id) VALUES ('%(fname)s','%(lname)s','%(hired)s','%(jobcode)s','%(storeid)s');"
  cnx = mysql.connector.connect(**dbconfig)
  cnx.autocommit = True
  cursor = cnx.cursor()

  def rnd_date():
    return time.strftime("%Y-%m-%d", (random.randrange(2000,2016), random.randrange(1,12), random.randrange(1,28), 0, 0, 0, 0, 1, -1))

  for x in range(num):
    if not shutdown_event.is_set():
      fname = genstring(3, 9)
      lname = genstring(4, 12)
      hired = rnd_date()
      jobcode = genstring(3, 3).upper()
      storeid = random.randrange(1, 20)

      cursor.execute(query % {u'fname': fname, u'lname': lname, u'hired': hired, u'jobcode': jobcode, u'storeid': storeid})

      if x % 1000 == 0:
        print "[%2d] Inserted %d rows" % (threadid, x)

  cnx.close()

... (more code) ...

  for x in range(8):
    t = threading.Thread(target=rnd_user, args=(125000,threadId,))
    t.start()