python/lib/django-0.96/django/db/backends/util.py

   1 import datetime
   2 from time import time
   3
   4 class CursorDebugWrapper(object):
   5     def __init__(self, cursor, db):
   6         self.cursor = cursor
   7         self.db = db
   8
   9     def execute(self, sql, params=()):
  10         start = time()
  11         try:
  12             return self.cursor.execute(sql, params)
  13         finally:
  14             stop = time()
  15             # If params was a list, convert it to a tuple, because string
  16             # formatting with '%' only works with tuples or dicts.
  17             if not isinstance(params, (tuple, dict)):
  18                 params = tuple(params)
  19             self.db.queries.append({
  20                 'sql': sql % params,
  21                 'time': "%.3f" % (stop - start),
  22             })
  23
  24     def executemany(self, sql, param_list):
  25         start = time()
  26         try:
  27             return self.cursor.executemany(sql, param_list)
  28         finally:
  29             stop = time()
  30             self.db.queries.append({
  31                 'sql': 'MANY: ' + sql + ' ' + str(tuple(param_list)),
  32                 'time': "%.3f" % (stop - start),
  33             })
  34
  35     def __getattr__(self, attr):
  36         if self.__dict__.has_key(attr):
  37             return self.__dict__[attr]
  38         else:
  39             return getattr(self.cursor, attr)
  40
  41 ###############################################
  42 # Converters from database (string) to Python #
  43 ###############################################
  44
  45 def typecast_date(s):
  46     return s and datetime.date(*map(int, s.split('-'))) or None # returns None if s is null
  47
  48 def typecast_time(s): # does NOT store time zone information
  49     if not s: return None
  50     hour, minutes, seconds = s.split(':')
  51     if '.' in seconds: # check whether seconds have a fractional part
  52         seconds, microseconds = seconds.split('.')
  53     else:
  54         microseconds = '0'
  55     return datetime.time(int(hour), int(minutes), int(seconds), int(float('.'+microseconds) * 1000000))
  56
  57 def typecast_timestamp(s): # does NOT store time zone information
  58     # "2005-07-29 15:48:00.590358-05"
  59     # "2005-07-29 09:56:00-05"
  60     if not s: return None
  61     if not ' ' in s: return typecast_date(s)
  62     d, t = s.split()
  63     # Extract timezone information, if it exists. Currently we just throw
  64     # it away, but in the future we may make use of it.
  65     if '-' in t:
  66         t, tz = t.split('-', 1)
  67         tz = '-' + tz
  68     elif '+' in t:
  69         t, tz = t.split('+', 1)
  70         tz = '+' + tz
  71     else:
  72         tz = ''
  73     dates = d.split('-')
  74     times = t.split(':')
  75     seconds = times[2]
  76     if '.' in seconds: # check whether seconds have a fractional part
  77         seconds, microseconds = seconds.split('.')
  78     else:
  79         microseconds = '0'
  80     return datetime.datetime(int(dates[0]), int(dates[1]), int(dates[2]),
  81         int(times[0]), int(times[1]), int(seconds), int(float('.'+microseconds) * 1000000))
  82
  83 def typecast_boolean(s):
  84     if s is None: return None
  85     if not s: return False
  86     return str(s)[0].lower() == 't'
  87
  88 ###############################################
  89 # Converters from Python to database (string) #
  90 ###############################################
  91
  92 def rev_typecast_boolean(obj, d):
  93     return obj and '1' or '0'
  94
  95 ##################################################################################
  96 # Helper functions for dictfetch* for databases that don't natively support them #
  97 ##################################################################################
  98
  99 def _dict_helper(desc, row):
 100     "Returns a dictionary for the given cursor.description and result row."
 101     return dict(zip([col[0] for col in desc], row))
 102
 103 def dictfetchone(cursor):
 104     "Returns a row from the cursor as a dict"
 105     row = cursor.fetchone()
 106     if not row:
 107         return None
 108     return _dict_helper(cursor.description, row)
 109
 110 def dictfetchmany(cursor, number):
 111     "Returns a certain number of rows from a cursor as a dict"
 112     desc = cursor.description
 113     for row in cursor.fetchmany(number):
 114         yield _dict_helper(desc, row)
 115
 116 def dictfetchall(cursor):
 117     "Returns all rows from a cursor as a dict"
 118     desc = cursor.description
 119     for row in cursor.fetchall():
 120         yield _dict_helper(desc, row)