def effective_default(self, field):
"""
Returns a field's effective database default value
"""
if field.has_default():
default = field.get_default()
elif not field.null and field.blank and field.empty_strings_allowed:
if field.get_internal_type() == "BinaryField":
default = six.binary_type()
else:
default = six.text_type()
elif getattr(field, 'auto_now', False) or getattr(
field, 'auto_now_add', False):
default = datetime.now()
internal_type = field.get_internal_type()
if internal_type == 'DateField':
default = default.date
elif internal_type == 'TimeField':
default = default.time
elif internal_type == 'DateTimeField':
default = timezone.now
else:
default = None
# If it's a callable, call it
if callable(default):
default = default()
# Run it through the field's get_db_prep_save method so we can send it
# to the database.
default = field.get_db_prep_save(default, self.connection)
return default
def default(self, o):
# See "Date Time String Format" in the ECMA-262 specification.
if isinstance(o, datetime.datetime):
r = o.isoformat()
if o.microsecond:
r = r[:23] + r[26:]
if r.endswith('+00:00'):
r = r[:-6] + 'Z'
return r
elif isinstance(o, datetime.date):
return o.isoformat()
elif isinstance(o, datetime.time):
if is_aware(o):
raise ValueError("JSON can't represent timezone-aware times.")
r = o.isoformat()
if o.microsecond:
r = r[:12]
return r
elif isinstance(o, decimal.Decimal):
return str(o)
elif isinstance(o, uuid.UUID):
return str(o)
elif isinstance(o, Promise):
return six.text_type(o)
else:
return super(DjangoJSONEncoder, self).default(o)
def get_prep_value(self, value):
"Returns field's value prepared for saving into a database."
value = super(FileField, self).get_prep_value(value)
# Need to convert File objects provided via a form to unicode for database insertion
if value is None:
return None
return six.text_type(value)
def last_executed_query(self, cursor, sql, params):
"""
Returns a string of the query last executed by the given cursor, with
placeholders replaced with actual values.
`sql` is the raw query containing placeholders, and `params` is the
sequence of parameters. These are used by default, but this method
exists for database backends to provide a better implementation
according to their own quoting schemes.
"""
# Convert params to contain Unicode values.
def to_unicode(s):
return force_text(s, strings_only=True, errors='replace')
if isinstance(params, (list, tuple)):
u_params = tuple(to_unicode(val) for val in params)
elif params is None:
u_params = ()
else:
u_params = {
to_unicode(k): to_unicode(v)
for k, v in params.items()
}
return six.text_type("QUERY = %r - PARAMS = %r") % (sql, u_params)
def quote_value(self, value):
# The backend "mostly works" without this function and there are use
# cases for compiling Python without the sqlite3 libraries (e.g.
# security hardening).
try:
import sqlite3
value = sqlite3.adapt(value)
except ImportError:
pass
except sqlite3.ProgrammingError:
pass
# Manual emulation of SQLite parameter quoting
if isinstance(value, type(True)):
return str(int(value))
elif isinstance(value, (Decimal, float)):
return str(value)
elif isinstance(value, six.integer_types):
return str(value)
elif isinstance(value, six.string_types):
return "'%s'" % six.text_type(value).replace("\'", "\'\'")
elif value is None:
return "NULL"
elif isinstance(value, (bytes, bytearray, six.memoryview)):
# Bytes are only allowed for BLOB fields, encoded as string
# literals containing hexadecimal data and preceded by a single "X"
# character:
# value = b'\x01\x02' => value_hex = b'0102' => return X'0102'
value = bytes(value)
hex_encoder = codecs.getencoder('hex_codec')
value_hex, _length = hex_encoder(value)
# Use 'ascii' encoding for b'01' => '01', no need to use force_text here.
return "X'%s'" % value_hex.decode('ascii')
else:
raise ValueError("Cannot quote parameter value %r of type %s" %
(value, type(value)))
def adapt_datetimefield_value(self, value):
"""
Transforms a datetime value to an object compatible with what is expected
by the backend driver for datetime columns.
"""
if value is None:
return None
return six.text_type(value)
def adapt_timefield_value(self, value):
if value is None:
return None
# SQLite doesn't support tz-aware datetimes
if timezone.is_aware(value):
raise ValueError("SQLite backend does not support timezone-aware times.")
return six.text_type(value)
def adapt_timefield_value(self, value):
"""
Transforms a time value to an object compatible with what is expected
by the backend driver for time columns.
"""
if value is None:
return None
if timezone.is_aware(value):
raise ValueError("Django does not support timezone-aware times.")
return six.text_type(value)
def adapt_datetimefield_value(self, value):
if value is None:
return None
# SQLite 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("SQLite backend does not support timezone-aware datetimes when USE_TZ is False.")
return six.text_type(value)
def quote_value(self, value):
if isinstance(value,
(datetime.date, datetime.time, datetime.datetime)):
return "'%s'" % value
elif isinstance(value, six.string_types):
return "'%s'" % six.text_type(value).replace("\'", "\'\'")
elif isinstance(value, six.buffer_types):
return "'%s'" % force_text(binascii.hexlify(value))
elif isinstance(value, bool):
return "1" if value else "0"
else:
return str(value)
def adapt_datetimefield_value(self, value):
if value is None:
return None
# MySQL 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(
"MySQL backend does not support timezone-aware datetimes when USE_TZ is False."
)
if not self.connection.features.supports_microsecond_precision:
value = value.replace(microsecond=0)
return six.text_type(value)
def T(self):
"""
Time zone of this machine; e.g. 'EST' or 'MDT'.
If timezone information is not available, this method returns
an empty string.
"""
if not self.timezone:
return ""
name = None
try:
name = self.timezone.tzname(self.data)
except Exception:
# pytz raises AmbiguousTimeError during the autumn DST change.
# This happens mainly when __init__ receives a naive datetime
# and sets self.timezone = get_default_timezone().
pass
if name is None:
name = self.format('O')
return six.text_type(name)
def y(self):
"Year, 2 digits; e.g. '99'"
return six.text_type(self.data.year)[2:]