def datetime_extract_sql(self, lookup_type, field_name, tzname):
# Django 1.6
if settings.USE_TZ:
field_name = "CONVERT_TZ({0}, 'UTC', %s)".format(field_name)
params = [tzname]
else:
params = []
# http://dev.mysql.com/doc/mysql/en/date-and-time-functions.html
if lookup_type == 'week_day':
# DAYOFWEEK() returns an integer, 1-7, Sunday=1.
# Note: WEEKDAY() returns 0-6, Monday=0.
sql = "DAYOFWEEK({0})".format(field_name)
else:
sql = "EXTRACT({0} FROM {1})".format(lookup_type.upper(),
field_name)
return sql, params
python类USE_TZ的实例源码
def datetime_trunc_sql(self, lookup_type, field_name, tzname):
# Django 1.6
if settings.USE_TZ:
field_name = "CONVERT_TZ({0}, 'UTC', %s)".format(field_name)
params = [tzname]
else:
params = []
fields = ['year', 'month', 'day', 'hour', 'minute', 'second']
format_ = ('%Y-', '%m', '-%d', ' %H:', '%i', ':%S')
format_def = ('0000-', '01', '-01', ' 00:', '00', ':00')
try:
i = fields.index(lookup_type) + 1
except ValueError:
sql = field_name
else:
format_str = ''.join([f for f in format_[:i]] +
[f for f in format_def[i:]])
sql = "CAST(DATE_FORMAT({0}, '{1}') AS DATETIME)".format(
field_name, format_str)
return sql, params
def value_to_db_datetime(self, value):
if value is None:
return None
# MySQL doesn't support tz-aware times
if timezone.is_aware(value):
if settings.USE_TZ:
value = value.astimezone(timezone.utc).replace(tzinfo=None)
else:
raise ValueError(
"MySQL backend does not support timezone-aware times."
)
if not self.connection.features.supports_microsecond_precision:
value = value.replace(microsecond=0)
if not self.connection.use_pure:
return datetime_to_mysql(value)
return self.connection.converter.to_mysql(value)
def from_current_timezone(value):
"""
When time zone support is enabled, convert naive datetimes
entered in the current time zone to aware datetimes.
"""
if settings.USE_TZ and value is not None and timezone.is_naive(value):
current_timezone = timezone.get_current_timezone()
try:
return timezone.make_aware(value, current_timezone)
except Exception:
message = _(
'%(datetime)s couldn\'t be interpreted '
'in time zone %(current_timezone)s; it '
'may be ambiguous or it may not exist.'
)
params = {'datetime': value, 'current_timezone': current_timezone}
six.reraise(ValidationError, ValidationError(
message,
code='ambiguous_timezone',
params=params,
), sys.exc_info()[2])
return value
def has_key(self, key, version=None):
key = self.make_key(key, version=version)
self.validate_key(key)
db = router.db_for_read(self.cache_model_class)
connection = connections[db]
table = connection.ops.quote_name(self._table)
if settings.USE_TZ:
now = datetime.utcnow()
else:
now = datetime.now()
now = now.replace(microsecond=0)
with connection.cursor() as cursor:
cursor.execute("SELECT cache_key FROM %s "
"WHERE cache_key = %%s and expires > %%s" % table,
[key, connection.ops.adapt_datetimefield_value(now)])
return cursor.fetchone() is not None
def adapt_datetime_warn_on_aware_datetime(value, conv):
# Remove this function and rely on the default adapter in Django 2.0.
if settings.USE_TZ and timezone.is_aware(value):
warnings.warn(
"The MySQL database adapter received an aware datetime (%s), "
"probably from cursor.execute(). Update your code to pass a "
"naive datetime in the database connection's time zone (UTC by "
"default).", RemovedInDjango20Warning)
# This doesn't account for the database connection's timezone,
# which isn't known. (That's why this adapter is deprecated.)
value = value.astimezone(timezone.utc).replace(tzinfo=None)
return Thing2Literal(value.strftime("%Y-%m-%d %H:%M:%S.%f"), conv)
# MySQLdb-1.2.1 returns TIME columns as timedelta -- they are more like
# timedelta in terms of actual behavior as they are signed and include days --
# and Django expects time, so we still need to override that. We also need to
# add special handling for SafeText and SafeBytes as MySQLdb's type
# checking is too tight to catch those (see Django ticket #6052).
def adapt_datetimefield_value(self, value):
"""
Transform a datetime value to an object compatible with what is expected
by the backend driver for datetime columns.
If naive datetime is passed assumes that is in UTC. Normally Django
models.DateTimeField makes sure that if USE_TZ is True passed datetime
is timezone aware.
"""
if value is None:
return None
# cx_Oracle doesn't support tz-aware datetimes
if timezone.is_aware(value):
if settings.USE_TZ:
value = timezone.make_naive(value, self.connection.timezone)
else:
raise ValueError("Oracle backend does not support timezone-aware datetimes when USE_TZ is False.")
return Oracle_datetime.from_datetime(value)
def year_lookup_bounds_for_datetime_field(self, value):
"""
Returns a two-elements list with the lower and upper bound to be used
with a BETWEEN operator to query a DateTimeField value using a year
lookup.
`value` is an int, containing the looked-up year.
"""
first = datetime.datetime(value, 1, 1)
second = datetime.datetime(value, 12, 31, 23, 59, 59, 999999)
if settings.USE_TZ:
tz = timezone.get_current_timezone()
first = timezone.make_aware(first, tz)
second = timezone.make_aware(second, tz)
first = self.adapt_datetimefield_value(first)
second = self.adapt_datetimefield_value(second)
return [first, second]
def timezone(self):
"""
Time zone for datetimes stored as naive values in the database.
Returns a tzinfo object or None.
This is only needed when time zone support is enabled and the database
doesn't support time zones. (When the database supports time zones,
the adapter handles aware datetimes so Django doesn't need to.)
"""
if not settings.USE_TZ:
return None
elif self.features.supports_timezones:
return None
elif self.settings_dict['TIME_ZONE'] is None:
return timezone.utc
else:
# Only this branch requires pytz.
return pytz.timezone(self.settings_dict['TIME_ZONE'])
def datetimes(self, field_name, kind, order='ASC', tzinfo=None):
"""
Returns a list of datetime objects representing all available
datetimes for the given field_name, scoped to 'kind'.
"""
assert kind in ("year", "month", "day", "hour", "minute", "second"), \
"'kind' must be one of 'year', 'month', 'day', 'hour', 'minute' or 'second'."
assert order in ('ASC', 'DESC'), \
"'order' must be either 'ASC' or 'DESC'."
if settings.USE_TZ:
if tzinfo is None:
tzinfo = timezone.get_current_timezone()
else:
tzinfo = None
return self.annotate(
datetimefield=DateTime(field_name, kind, tzinfo),
plain_field=F(field_name)
).values_list(
'datetimefield', flat=True
).distinct().filter(plain_field__isnull=False).order_by(('-' if order == 'DESC' else '') + 'datetimefield')
def get_prep_value(self, value):
value = super(DateTimeField, self).get_prep_value(value)
value = self.to_python(value)
if value is not None and settings.USE_TZ and timezone.is_naive(value):
# For backwards compatibility, interpret naive datetimes in local
# time. This won't work during DST change, but we can't do much
# about it, so we let the exceptions percolate up the call stack.
try:
name = '%s.%s' % (self.model.__name__, self.name)
except AttributeError:
name = '(unbound)'
warnings.warn("DateTimeField %s received a naive datetime (%s)"
" while time zone support is active." %
(name, value),
RuntimeWarning)
default_timezone = timezone.get_default_timezone()
value = timezone.make_aware(value, default_timezone)
return value
def template_localtime(value, use_tz=None):
"""
Checks if value is a datetime and converts it to local time if necessary.
If use_tz is provided and is not None, that will force the value to
be converted (or not), overriding the value of settings.USE_TZ.
This function is designed for use by the template engine.
"""
should_convert = (isinstance(value, datetime)
and (settings.USE_TZ if use_tz is None else use_tz)
and not is_naive(value)
and getattr(value, 'convert_to_local_time', True))
return localtime(value) if should_convert else value
# Utilities
def from_current_timezone(value):
"""
When time zone support is enabled, convert naive datetimes
entered in the current time zone to aware datetimes.
"""
if settings.USE_TZ and value is not None and timezone.is_naive(value):
current_timezone = timezone.get_current_timezone()
try:
return timezone.make_aware(value, current_timezone)
except Exception:
message = _(
'%(datetime)s couldn\'t be interpreted '
'in time zone %(current_timezone)s; it '
'may be ambiguous or it may not exist.'
)
params = {'datetime': value, 'current_timezone': current_timezone}
six.reraise(ValidationError, ValidationError(
message,
code='ambiguous_timezone',
params=params,
), sys.exc_info()[2])
return value
def has_key(self, key, version=None):
key = self.make_key(key, version=version)
self.validate_key(key)
db = router.db_for_read(self.cache_model_class)
connection = connections[db]
table = connection.ops.quote_name(self._table)
if settings.USE_TZ:
now = datetime.utcnow()
else:
now = datetime.now()
now = now.replace(microsecond=0)
with connection.cursor() as cursor:
cursor.execute("SELECT cache_key FROM %s "
"WHERE cache_key = %%s and expires > %%s" % table,
[key, connection.ops.adapt_datetimefield_value(now)])
return cursor.fetchone() is not None
def from_current_timezone(value):
"""
When time zone support is enabled, convert naive datetimes
entered in the current time zone to aware datetimes.
"""
if settings.USE_TZ and value is not None and timezone.is_naive(value):
current_timezone = timezone.get_current_timezone()
try:
return timezone.make_aware(value, current_timezone)
except Exception:
message = _(
'%(datetime)s couldn\'t be interpreted '
'in time zone %(current_timezone)s; it '
'may be ambiguous or it may not exist.'
)
params = {'datetime': value, 'current_timezone': current_timezone}
six.reraise(ValidationError, ValidationError(
message,
code='ambiguous_timezone',
params=params,
), sys.exc_info()[2])
return value
def has_key(self, key, version=None):
key = self.make_key(key, version=version)
self.validate_key(key)
db = router.db_for_read(self.cache_model_class)
connection = connections[db]
table = connection.ops.quote_name(self._table)
if settings.USE_TZ:
now = datetime.utcnow()
else:
now = datetime.now()
now = now.replace(microsecond=0)
with connection.cursor() as cursor:
cursor.execute("SELECT cache_key FROM %s "
"WHERE cache_key = %%s and expires > %%s" % table,
[key, connection.ops.adapt_datetimefield_value(now)])
return cursor.fetchone() is not None
def datetime_extract_sql(self, lookup_type, field_name, tzname):
# Django 1.6
if settings.USE_TZ:
field_name = "CONVERT_TZ({0}, 'UTC', %s)".format(field_name)
params = [tzname]
else:
params = []
# http://dev.mysql.com/doc/mysql/en/date-and-time-functions.html
if lookup_type == 'week_day':
# DAYOFWEEK() returns an integer, 1-7, Sunday=1.
# Note: WEEKDAY() returns 0-6, Monday=0.
sql = "DAYOFWEEK({0})".format(field_name)
else:
sql = "EXTRACT({0} FROM {1})".format(lookup_type.upper(),
field_name)
return sql, params
def datetime_trunc_sql(self, lookup_type, field_name, tzname):
# Django 1.6
if settings.USE_TZ:
field_name = "CONVERT_TZ({0}, 'UTC', %s)".format(field_name)
params = [tzname]
else:
params = []
fields = ['year', 'month', 'day', 'hour', 'minute', 'second']
format_ = ('%Y-', '%m', '-%d', ' %H:', '%i', ':%S')
format_def = ('0000-', '01', '-01', ' 00:', '00', ':00')
try:
i = fields.index(lookup_type) + 1
except ValueError:
sql = field_name
else:
format_str = ''.join([f for f in format_[:i]] +
[f for f in format_def[i:]])
sql = "CAST(DATE_FORMAT({0}, '{1}') AS DATETIME)".format(
field_name, format_str)
return sql, params
def value_to_db_datetime(self, value):
if value is None:
return None
# MySQL doesn't support tz-aware times
if timezone.is_aware(value):
if settings.USE_TZ:
value = value.astimezone(timezone.utc).replace(tzinfo=None)
else:
raise ValueError(
"MySQL backend does not support timezone-aware times."
)
if not self.connection.features.supports_microsecond_precision:
value = value.replace(microsecond=0)
if not self.connection.use_pure:
return datetime_to_mysql(value)
return self.connection.converter.to_mysql(value)
def _DATETIME_to_python(self, value, dsc=None):
"""Connector/Python always returns naive datetime.datetime
Connector/Python always returns naive timestamps since MySQL has
no time zone support. Since Django needs non-naive, we need to add
the UTC time zone.
Returns datetime.datetime()
"""
if not value:
return None
dt = MySQLConverter._DATETIME_to_python(self, value)
if dt is None:
return None
if settings.USE_TZ and timezone.is_naive(dt):
dt = dt.replace(tzinfo=timezone.utc)
return dt
def from_current_timezone(value):
"""
When time zone support is enabled, convert naive datetimes
entered in the current time zone to aware datetimes.
"""
if settings.USE_TZ and value is not None and timezone.is_naive(value):
current_timezone = timezone.get_current_timezone()
try:
return timezone.make_aware(value, current_timezone)
except Exception:
message = _(
'%(datetime)s couldn\'t be interpreted '
'in time zone %(current_timezone)s; it '
'may be ambiguous or it may not exist.'
)
params = {'datetime': value, 'current_timezone': current_timezone}
six.reraise(ValidationError, ValidationError(
message,
code='ambiguous_timezone',
params=params,
), sys.exc_info()[2])
return value
def has_key(self, key, version=None):
key = self.make_key(key, version=version)
self.validate_key(key)
db = router.db_for_read(self.cache_model_class)
connection = connections[db]
table = connection.ops.quote_name(self._table)
if settings.USE_TZ:
now = datetime.utcnow()
else:
now = datetime.now()
now = now.replace(microsecond=0)
with connection.cursor() as cursor:
cursor.execute("SELECT cache_key FROM %s "
"WHERE cache_key = %%s and expires > %%s" % table,
[key, connection.ops.adapt_datetimefield_value(now)])
return cursor.fetchone() is not None
def datetime_extract_sql(self, lookup_type, field_name, tzname):
# Django 1.6
if settings.USE_TZ:
field_name = "CONVERT_TZ({0}, 'UTC', %s)".format(field_name)
params = [tzname]
else:
params = []
# http://dev.mysql.com/doc/mysql/en/date-and-time-functions.html
if lookup_type == 'week_day':
# DAYOFWEEK() returns an integer, 1-7, Sunday=1.
# Note: WEEKDAY() returns 0-6, Monday=0.
sql = "DAYOFWEEK({0})".format(field_name)
else:
sql = "EXTRACT({0} FROM {1})".format(lookup_type.upper(),
field_name)
return sql, params
def datetime_trunc_sql(self, lookup_type, field_name, tzname):
# Django 1.6
if settings.USE_TZ:
field_name = "CONVERT_TZ({0}, 'UTC', %s)".format(field_name)
params = [tzname]
else:
params = []
fields = ['year', 'month', 'day', 'hour', 'minute', 'second']
format_ = ('%Y-', '%m', '-%d', ' %H:', '%i', ':%S')
format_def = ('0000-', '01', '-01', ' 00:', '00', ':00')
try:
i = fields.index(lookup_type) + 1
except ValueError:
sql = field_name
else:
format_str = ''.join([f for f in format_[:i]] +
[f for f in format_def[i:]])
sql = "CAST(DATE_FORMAT({0}, '{1}') AS DATETIME)".format(
field_name, format_str)
return sql, params
def value_to_db_datetime(self, value):
if value is None:
return None
# MySQL doesn't support tz-aware times
if timezone.is_aware(value):
if settings.USE_TZ:
value = value.astimezone(timezone.utc).replace(tzinfo=None)
else:
raise ValueError(
"MySQL backend does not support timezone-aware times."
)
if not self.connection.features.supports_microsecond_precision:
value = value.replace(microsecond=0)
if not self.connection.use_pure:
return datetime_to_mysql(value)
return self.connection.converter.to_mysql(value)
def _DATETIME_to_python(self, value, dsc=None):
"""Connector/Python always returns naive datetime.datetime
Connector/Python always returns naive timestamps since MySQL has
no time zone support. Since Django needs non-naive, we need to add
the UTC time zone.
Returns datetime.datetime()
"""
if not value:
return None
dt = MySQLConverter._DATETIME_to_python(self, value)
if dt is None:
return None
if settings.USE_TZ and timezone.is_naive(dt):
dt = dt.replace(tzinfo=timezone.utc)
return dt
def _format_parameters( self, parameters ):
parameters = list( parameters )
for index in range( len( parameters ) ):
# With raw SQL queries, datetimes can reach this function
# without being converted by DateTimeField.get_db_prep_value.
if settings.USE_TZ and isinstance( parameters[index], datetime.datetime ):
param = parameters[index]
if timezone.is_naive( param ):
warnings.warn(u"Received a naive datetime (%s)"
u" while time zone support is active." % param,
RuntimeWarning)
default_timezone = timezone.get_default_timezone()
param = timezone.make_aware( param, default_timezone )
param = param.astimezone(timezone.utc).replace(tzinfo=None)
parameters[index] = param
return tuple( parameters )
# Over-riding this method to modify SQLs which contains format parameter to qmark.
def datetime_extract_sql(self, lookup_type, field_name, tzname):
if settings.USE_TZ:
hr, min = self._get_utcoffset(tzname)
if hr < 0:
field_name = "%s - %s HOURS - %s MINUTES" % (field_name, -hr, -min)
else:
field_name = "%s + %s HOURS + %s MINUTES" % (field_name, hr, min)
if lookup_type.upper() == 'WEEK_DAY':
return " DAYOFWEEK(%s) " % ( field_name ), []
else:
return " %s(%s) " % ( lookup_type.upper(), field_name ), []
# Truncating the date value on the basic of lookup type.
# e.g If input is 2008-12-04 and month then output will be 2008-12-01 00:00:00
# Reference: http://www.ibm.com/developerworks/data/library/samples/db2/0205udfs/index.html
def datetime_trunc_sql( self, lookup_type, field_name, tzname ):
sql = "TIMESTAMP(SUBSTR(CHAR(%s), 1, %d) || '%s')"
if settings.USE_TZ:
hr, min = self._get_utcoffset(tzname)
if hr < 0:
field_name = "%s - %s HOURS - %s MINUTES" % (field_name, -hr, -min)
else:
field_name = "%s + %s HOURS + %s MINUTES" % (field_name, hr, min)
if lookup_type.upper() == 'SECOND':
sql = sql % ( field_name, 19, '.000000' )
if lookup_type.upper() == 'MINUTE':
sql = sql % ( field_name, 16, '.00.000000' )
elif lookup_type.upper() == 'HOUR':
sql = sql % ( field_name, 13, '.00.00.000000' )
elif lookup_type.upper() == 'DAY':
sql = sql % ( field_name, 10, '-00.00.00.000000' )
elif lookup_type.upper() == 'MONTH':
sql = sql % ( field_name, 7, '-01-00.00.00.000000' )
elif lookup_type.upper() == 'YEAR':
sql = sql % ( field_name, 4, '-01-01-00.00.00.000000' )
return sql, []
def value_to_db_datetime( self, value ):
if value is None:
return None
if( djangoVersion[0:2] <= ( 1, 3 ) ):
#DB2 doesn't support time zone aware datetime
if ( value.tzinfo is not None ):
raise ValueError( "Timezone aware datetime not supported" )
else:
return value
else:
if is_aware(value):
if settings.USE_TZ:
value = value.astimezone( utc ).replace( tzinfo=None )
else:
raise ValueError( "Timezone aware datetime not supported" )
return unicode( value )
