307 lines
12 KiB
Python
307 lines
12 KiB
Python
"""
|
|
Implementations of SQL functions for SQLite.
|
|
"""
|
|
import functools
|
|
import operator
|
|
import random
|
|
import statistics
|
|
from datetime import timedelta
|
|
from hashlib import sha1, sha224, sha256, sha384, sha512
|
|
from math import (
|
|
acos, asin, atan, atan2, ceil, cos, degrees, exp, floor, fmod, log, pi,
|
|
radians, sin, sqrt, tan,
|
|
)
|
|
from re import search as re_search
|
|
|
|
from django.db.backends.base.base import timezone_constructor
|
|
from django.db.backends.utils import (
|
|
split_tzname_delta, typecast_time, typecast_timestamp,
|
|
)
|
|
from django.utils import timezone
|
|
from django.utils.crypto import md5
|
|
from django.utils.duration import duration_microseconds
|
|
|
|
|
|
def none_guard(func):
|
|
"""
|
|
Decorator that returns None if any of the arguments to the decorated
|
|
function are None. Many SQL functions return NULL if any of their arguments
|
|
are NULL. This decorator simplifies the implementation of this for the
|
|
custom functions registered below.
|
|
"""
|
|
@functools.wraps(func)
|
|
def wrapper(*args, **kwargs):
|
|
return None if None in args else func(*args, **kwargs)
|
|
return wrapper
|
|
|
|
|
|
def list_aggregate(function):
|
|
"""
|
|
Return an aggregate class that accumulates values in a list and applies
|
|
the provided function to the data.
|
|
"""
|
|
return type('ListAggregate', (list,), {'finalize': function, 'step': list.append})
|
|
|
|
|
|
def register(connection):
|
|
create_deterministic_function = functools.partial(
|
|
connection.create_function,
|
|
deterministic=True,
|
|
)
|
|
create_deterministic_function('django_date_extract', 2, _sqlite_datetime_extract)
|
|
create_deterministic_function('django_date_trunc', 4, _sqlite_date_trunc)
|
|
create_deterministic_function('django_datetime_cast_date', 3, _sqlite_datetime_cast_date)
|
|
create_deterministic_function('django_datetime_cast_time', 3, _sqlite_datetime_cast_time)
|
|
create_deterministic_function('django_datetime_extract', 4, _sqlite_datetime_extract)
|
|
create_deterministic_function('django_datetime_trunc', 4, _sqlite_datetime_trunc)
|
|
create_deterministic_function('django_time_extract', 2, _sqlite_time_extract)
|
|
create_deterministic_function('django_time_trunc', 4, _sqlite_time_trunc)
|
|
create_deterministic_function('django_time_diff', 2, _sqlite_time_diff)
|
|
create_deterministic_function('django_timestamp_diff', 2, _sqlite_timestamp_diff)
|
|
create_deterministic_function('django_format_dtdelta', 3, _sqlite_format_dtdelta)
|
|
create_deterministic_function('regexp', 2, _sqlite_regexp)
|
|
create_deterministic_function('ACOS', 1, none_guard(acos))
|
|
create_deterministic_function('ASIN', 1, none_guard(asin))
|
|
create_deterministic_function('ATAN', 1, none_guard(atan))
|
|
create_deterministic_function('ATAN2', 2, none_guard(atan2))
|
|
create_deterministic_function('BITXOR', 2, none_guard(operator.xor))
|
|
create_deterministic_function('CEILING', 1, none_guard(ceil))
|
|
create_deterministic_function('COS', 1, none_guard(cos))
|
|
create_deterministic_function('COT', 1, none_guard(lambda x: 1 / tan(x)))
|
|
create_deterministic_function('DEGREES', 1, none_guard(degrees))
|
|
create_deterministic_function('EXP', 1, none_guard(exp))
|
|
create_deterministic_function('FLOOR', 1, none_guard(floor))
|
|
create_deterministic_function('LN', 1, none_guard(log))
|
|
create_deterministic_function('LOG', 2, none_guard(lambda x, y: log(y, x)))
|
|
create_deterministic_function('LPAD', 3, _sqlite_lpad)
|
|
create_deterministic_function('MD5', 1, none_guard(lambda x: md5(x.encode()).hexdigest()))
|
|
create_deterministic_function('MOD', 2, none_guard(fmod))
|
|
create_deterministic_function('PI', 0, lambda: pi)
|
|
create_deterministic_function('POWER', 2, none_guard(operator.pow))
|
|
create_deterministic_function('RADIANS', 1, none_guard(radians))
|
|
create_deterministic_function('REPEAT', 2, none_guard(operator.mul))
|
|
create_deterministic_function('REVERSE', 1, none_guard(lambda x: x[::-1]))
|
|
create_deterministic_function('RPAD', 3, _sqlite_rpad)
|
|
create_deterministic_function('SHA1', 1, none_guard(lambda x: sha1(x.encode()).hexdigest()))
|
|
create_deterministic_function('SHA224', 1, none_guard(lambda x: sha224(x.encode()).hexdigest()))
|
|
create_deterministic_function('SHA256', 1, none_guard(lambda x: sha256(x.encode()).hexdigest()))
|
|
create_deterministic_function('SHA384', 1, none_guard(lambda x: sha384(x.encode()).hexdigest()))
|
|
create_deterministic_function('SHA512', 1, none_guard(lambda x: sha512(x.encode()).hexdigest()))
|
|
create_deterministic_function('SIGN', 1, none_guard(lambda x: (x > 0) - (x < 0)))
|
|
create_deterministic_function('SIN', 1, none_guard(sin))
|
|
create_deterministic_function('SQRT', 1, none_guard(sqrt))
|
|
create_deterministic_function('TAN', 1, none_guard(tan))
|
|
# Don't use the built-in RANDOM() function because it returns a value
|
|
# in the range [-1 * 2^63, 2^63 - 1] instead of [0, 1).
|
|
connection.create_function('RAND', 0, random.random)
|
|
connection.create_aggregate('STDDEV_POP', 1, list_aggregate(statistics.pstdev))
|
|
connection.create_aggregate('STDDEV_SAMP', 1, list_aggregate(statistics.stdev))
|
|
connection.create_aggregate('VAR_POP', 1, list_aggregate(statistics.pvariance))
|
|
connection.create_aggregate('VAR_SAMP', 1, list_aggregate(statistics.variance))
|
|
|
|
|
|
def _sqlite_datetime_parse(dt, tzname=None, conn_tzname=None):
|
|
if dt is None:
|
|
return None
|
|
try:
|
|
dt = typecast_timestamp(dt)
|
|
except (TypeError, ValueError):
|
|
return None
|
|
if conn_tzname:
|
|
dt = dt.replace(tzinfo=timezone_constructor(conn_tzname))
|
|
if tzname is not None and tzname != conn_tzname:
|
|
tzname, sign, offset = split_tzname_delta(tzname)
|
|
if offset:
|
|
hours, minutes = offset.split(':')
|
|
offset_delta = timedelta(hours=int(hours), minutes=int(minutes))
|
|
dt += offset_delta if sign == '+' else -offset_delta
|
|
dt = timezone.localtime(dt, timezone_constructor(tzname))
|
|
return dt
|
|
|
|
|
|
def _sqlite_date_trunc(lookup_type, dt, tzname, conn_tzname):
|
|
dt = _sqlite_datetime_parse(dt, tzname, conn_tzname)
|
|
if dt is None:
|
|
return None
|
|
if lookup_type == 'year':
|
|
return f'{dt.year:04d}-01-01'
|
|
elif lookup_type == 'quarter':
|
|
month_in_quarter = dt.month - (dt.month - 1) % 3
|
|
return f'{dt.year:04d}-{month_in_quarter:02d}-01'
|
|
elif lookup_type == 'month':
|
|
return f'{dt.year:04d}-{dt.month:02d}-01'
|
|
elif lookup_type == 'week':
|
|
dt = dt - timedelta(days=dt.weekday())
|
|
return f'{dt.year:04d}-{dt.month:02d}-{dt.day:02d}'
|
|
elif lookup_type == 'day':
|
|
return f'{dt.year:04d}-{dt.month:02d}-{dt.day:02d}'
|
|
raise ValueError(f'Unsupported lookup type: {lookup_type!r}')
|
|
|
|
|
|
def _sqlite_time_trunc(lookup_type, dt, tzname, conn_tzname):
|
|
if dt is None:
|
|
return None
|
|
dt_parsed = _sqlite_datetime_parse(dt, tzname, conn_tzname)
|
|
if dt_parsed is None:
|
|
try:
|
|
dt = typecast_time(dt)
|
|
except (ValueError, TypeError):
|
|
return None
|
|
else:
|
|
dt = dt_parsed
|
|
if lookup_type == 'hour':
|
|
return f'{dt.hour:02d}:00:00'
|
|
elif lookup_type == 'minute':
|
|
return f'{dt.hour:02d}:{dt.minute:02d}:00'
|
|
elif lookup_type == 'second':
|
|
return f'{dt.hour:02d}:{dt.minute:02d}:{dt.second:02d}'
|
|
raise ValueError(f'Unsupported lookup type: {lookup_type!r}')
|
|
|
|
|
|
def _sqlite_datetime_cast_date(dt, tzname, conn_tzname):
|
|
dt = _sqlite_datetime_parse(dt, tzname, conn_tzname)
|
|
if dt is None:
|
|
return None
|
|
return dt.date().isoformat()
|
|
|
|
|
|
def _sqlite_datetime_cast_time(dt, tzname, conn_tzname):
|
|
dt = _sqlite_datetime_parse(dt, tzname, conn_tzname)
|
|
if dt is None:
|
|
return None
|
|
return dt.time().isoformat()
|
|
|
|
|
|
def _sqlite_datetime_extract(lookup_type, dt, tzname=None, conn_tzname=None):
|
|
dt = _sqlite_datetime_parse(dt, tzname, conn_tzname)
|
|
if dt is None:
|
|
return None
|
|
if lookup_type == 'week_day':
|
|
return (dt.isoweekday() % 7) + 1
|
|
elif lookup_type == 'iso_week_day':
|
|
return dt.isoweekday()
|
|
elif lookup_type == 'week':
|
|
return dt.isocalendar()[1]
|
|
elif lookup_type == 'quarter':
|
|
return ceil(dt.month / 3)
|
|
elif lookup_type == 'iso_year':
|
|
return dt.isocalendar()[0]
|
|
else:
|
|
return getattr(dt, lookup_type)
|
|
|
|
|
|
def _sqlite_datetime_trunc(lookup_type, dt, tzname, conn_tzname):
|
|
dt = _sqlite_datetime_parse(dt, tzname, conn_tzname)
|
|
if dt is None:
|
|
return None
|
|
if lookup_type == 'year':
|
|
return f'{dt.year:04d}-01-01 00:00:00'
|
|
elif lookup_type == 'quarter':
|
|
month_in_quarter = dt.month - (dt.month - 1) % 3
|
|
return f'{dt.year:04d}-{month_in_quarter:02d}-01 00:00:00'
|
|
elif lookup_type == 'month':
|
|
return f'{dt.year:04d}-{dt.month:02d}-01 00:00:00'
|
|
elif lookup_type == 'week':
|
|
dt = dt - timedelta(days=dt.weekday())
|
|
return f'{dt.year:04d}-{dt.month:02d}-{dt.day:02d} 00:00:00'
|
|
elif lookup_type == 'day':
|
|
return f'{dt.year:04d}-{dt.month:02d}-{dt.day:02d} 00:00:00'
|
|
elif lookup_type == 'hour':
|
|
return f'{dt.year:04d}-{dt.month:02d}-{dt.day:02d} {dt.hour:02d}:00:00'
|
|
elif lookup_type == 'minute':
|
|
return f'{dt.year:04d}-{dt.month:02d}-{dt.day:02d} {dt.hour:02d}:{dt.minute:02d}:00'
|
|
elif lookup_type == 'second':
|
|
return f'{dt.year:04d}-{dt.month:02d}-{dt.day:02d} {dt.hour:02d}:{dt.minute:02d}:{dt.second:02d}'
|
|
raise ValueError(f'Unsupported lookup type: {lookup_type!r}')
|
|
|
|
|
|
def _sqlite_time_extract(lookup_type, dt):
|
|
if dt is None:
|
|
return None
|
|
try:
|
|
dt = typecast_time(dt)
|
|
except (ValueError, TypeError):
|
|
return None
|
|
return getattr(dt, lookup_type)
|
|
|
|
|
|
def _sqlite_prepare_dtdelta_param(conn, param):
|
|
if conn in ['+', '-']:
|
|
if isinstance(param, int):
|
|
return timedelta(0, 0, param)
|
|
else:
|
|
return typecast_timestamp(param)
|
|
return param
|
|
|
|
|
|
@none_guard
|
|
def _sqlite_format_dtdelta(connector, lhs, rhs):
|
|
"""
|
|
LHS and RHS can be either:
|
|
- An integer number of microseconds
|
|
- A string representing a datetime
|
|
- A scalar value, e.g. float
|
|
"""
|
|
connector = connector.strip()
|
|
try:
|
|
real_lhs = _sqlite_prepare_dtdelta_param(connector, lhs)
|
|
real_rhs = _sqlite_prepare_dtdelta_param(connector, rhs)
|
|
except (ValueError, TypeError):
|
|
return None
|
|
if connector == '+':
|
|
# typecast_timestamp() returns a date or a datetime without timezone.
|
|
# It will be formatted as "%Y-%m-%d" or "%Y-%m-%d %H:%M:%S[.%f]"
|
|
out = str(real_lhs + real_rhs)
|
|
elif connector == '-':
|
|
out = str(real_lhs - real_rhs)
|
|
elif connector == '*':
|
|
out = real_lhs * real_rhs
|
|
else:
|
|
out = real_lhs / real_rhs
|
|
return out
|
|
|
|
|
|
@none_guard
|
|
def _sqlite_time_diff(lhs, rhs):
|
|
left = typecast_time(lhs)
|
|
right = typecast_time(rhs)
|
|
return (
|
|
(left.hour * 60 * 60 * 1000000) +
|
|
(left.minute * 60 * 1000000) +
|
|
(left.second * 1000000) +
|
|
(left.microsecond) -
|
|
(right.hour * 60 * 60 * 1000000) -
|
|
(right.minute * 60 * 1000000) -
|
|
(right.second * 1000000) -
|
|
(right.microsecond)
|
|
)
|
|
|
|
|
|
@none_guard
|
|
def _sqlite_timestamp_diff(lhs, rhs):
|
|
left = typecast_timestamp(lhs)
|
|
right = typecast_timestamp(rhs)
|
|
return duration_microseconds(left - right)
|
|
|
|
|
|
@none_guard
|
|
def _sqlite_regexp(pattern, string):
|
|
if not isinstance(string, str):
|
|
string = str(string)
|
|
return bool(re_search(pattern, string))
|
|
|
|
|
|
@none_guard
|
|
def _sqlite_lpad(text, length, fill_text):
|
|
delta = length - len(text)
|
|
if delta <= 0:
|
|
return text[:length]
|
|
return (fill_text * length)[:delta] + text
|
|
|
|
|
|
@none_guard
|
|
def _sqlite_rpad(text, length, fill_text):
|
|
if text is None or length is None or fill_text is None:
|
|
return None
|
|
return (text + fill_text * length)[:length]
|