获取django框架orm query执行的sql语句实现方法分析

 queryset = MyModel.objects.all()
 print 'query sql: ' + str(queryset .query)
 #result:

from django.db import connections
connections['default'].queries

from django.db import connection
from django.conf import settings
import os
def terminal_width():
  """
  Function to compute the terminal width.
  WARNING: This is not my code, but I've been using it forever and
  I don't remember where it came from.
  """
  width = 0
  try:
    import struct, fcntl, termios
    s = struct.pack('HHHH', 0, 0, 0, 0)
    x = fcntl.ioctl(1, termios.TIOCGWINSZ, s)
    width = struct.unpack('HHHH', x)[1]
  except:
    pass
  if width <= 0:
    try:
      width = int(os.environ['COLUMNS'])
    except:
      pass
  if width <= 0:
    width = 80
  return width
class SqlPrintingMiddleware(object):
  """
  Middleware which prints out a list of all SQL queries done
  for each view that is processed. This is only useful for debugging.
  """
  def process_response(self, request, response):
    indentation = 2
    if len(connection.queries) > 0 and settings.DEBUG:
      width = terminal_width()
      total_time = 0.0
      for query in connection.queries:
        nice_sql = query['sql'].replace('"', '').replace(',',', ')
        sql = "\033[1;31m[%s]\033[0m %s" % (query['time'], nice_sql)
        total_time = total_time + float(query['time'])
        while len(sql) > width-indentation:
          print "%s%s" % (" "*indentation, sql[:width-indentation])
          sql = sql[width-indentation:]
        print "%s%s\n" % (" "*indentation, sql)
      replace_tuple = (" "*indentation, str(total_time))
      print "%s\033[1;32m[TOTAL TIME: %s seconds]\033[0m" % replace_tuple
    return response

MIDDLEWARE_CLASSES = (
  'django.middleware.common.CommonMiddleware',
  'django.contrib.sessions.middleware.SessionMiddleware',
  'django.middleware.csrf.CsrfViewMiddleware',
  'django.contrib.auth.middleware.AuthenticationMiddleware',
  'django.contrib.messages.middleware.MessageMiddleware',
  'yihaomen.common.mymiddleware.SqlPrintingMiddleware', # 这是增加的显示sql语句的middleware
  # Uncomment the next line for simple clickjacking protection:
  # 'django.middleware.clickjacking.XFrameOptionsMiddleware',
)