"""
Implementations of SQL functions for SQLite.
"""
import functools
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 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("BITXOR", 2, _sqlite_bitxor)
create_deterministic_function("COT", 1, _sqlite_cot)
create_deterministic_function("LPAD", 3, _sqlite_lpad)
create_deterministic_function("MD5", 1, _sqlite_md5)
create_deterministic_function("REPEAT", 2, _sqlite_repeat)
create_deterministic_function("REVERSE", 1, _sqlite_reverse)
create_deterministic_function("RPAD", 3, _sqlite_rpad)
create_deterministic_function("SHA1", 1, _sqlite_sha1)
create_deterministic_function("SHA224", 1, _sqlite_sha224)
create_deterministic_function("SHA256", 1, _sqlite_sha256)
create_deterministic_function("SHA384", 1, _sqlite_sha384)
create_deterministic_function("SHA512", 1, _sqlite_sha512)
create_deterministic_function("SIGN", 1, _sqlite_sign)
# 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, StdDevPop)
connection.create_aggregate("STDDEV_SAMP", 1, StdDevSamp)
connection.create_aggregate("VAR_POP", 1, VarPop)
connection.create_aggregate("VAR_SAMP", 1, VarSamp)
# Some math functions are enabled by default in SQLite 3.35+.
sql = "select sqlite_compileoption_used('ENABLE_MATH_FUNCTIONS')"
if not connection.execute(sql).fetchone()[0]:
create_deterministic_function("ACOS", 1, _sqlite_acos)
create_deterministic_function("ASIN", 1, _sqlite_asin)
create_deterministic_function("ATAN", 1, _sqlite_atan)
create_deterministic_function("ATAN2", 2, _sqlite_atan2)
create_deterministic_function("CEILING", 1, _sqlite_ceiling)
create_deterministic_function("COS", 1, _sqlite_cos)
create_deterministic_function("DEGREES", 1, _sqlite_degrees)
create_deterministic_function("EXP", 1, _sqlite_exp)
create_deterministic_function("FLOOR", 1, _sqlite_floor)
create_deterministic_function("LN", 1, _sqlite_ln)
create_deterministic_function("LOG", 2, _sqlite_log)
create_deterministic_function("MOD", 2, _sqlite_mod)
create_deterministic_function("PI", 0, _sqlite_pi)
create_deterministic_function("POWER", 2, _sqlite_power)
create_deterministic_function("RADIANS", 1, _sqlite_radians)
create_deterministic_function("SIN", 1, _sqlite_sin)
create_deterministic_function("SQRT", 1, _sqlite_sqrt)
create_deterministic_function("TAN", 1, _sqlite_tan)
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} "
f"{dt.hour:02d}:{dt.minute:02d}:00"
)
elif lookup_type == "second":
return (
f"{dt.year:04d}-{dt.month:02d}-{dt.day:02d} "
f"{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
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
"""
if connector is None or lhs is None or rhs is None:
return None
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
def _sqlite_time_diff(lhs, rhs):
if lhs is None or rhs is None:
return None
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)
)
def _sqlite_timestamp_diff(lhs, rhs):
if lhs is None or rhs is None:
return None
left = typecast_timestamp(lhs)
right = typecast_timestamp(rhs)
return duration_microseconds(left - right)
def _sqlite_regexp(pattern, string):
if pattern is None or string is None:
return None
if not isinstance(string, str):
string = str(string)
return bool(re_search(pattern, string))
def _sqlite_acos(x):
if x is None:
return None
return acos(x)
def _sqlite_asin(x):
if x is None:
return None
return asin(x)
def _sqlite_atan(x):
if x is None:
return None
return atan(x)
def _sqlite_atan2(y, x):
if y is None or x is None:
return None
return atan2(y, x)
def _sqlite_bitxor(x, y):
if x is None or y is None:
return None
return x ^ y
def _sqlite_ceiling(x):
if x is None:
return None
return ceil(x)
def _sqlite_cos(x):
if x is None:
return None
return cos(x)
def _sqlite_cot(x):
if x is None:
return None
return 1 / tan(x)
def _sqlite_degrees(x):
if x is None:
return None
return degrees(x)
def _sqlite_exp(x):
if x is None:
return None
return exp(x)
def _sqlite_floor(x):
if x is None:
return None
return floor(x)
def _sqlite_ln(x):
if x is None:
return None
return log(x)
def _sqlite_log(base, x):
if base is None or x is None:
return None
# Arguments reversed to match SQL standard.
return log(x, base)
def _sqlite_lpad(text, length, fill_text):
if text is None or length is None or fill_text is None:
return None
delta = length - len(text)
if delta <= 0:
return text[:length]
return (fill_text * length)[:delta] + text
def _sqlite_md5(text):
if text is None:
return None
return md5(text.encode()).hexdigest()
def _sqlite_mod(x, y):
if x is None or y is None:
return None
return fmod(x, y)
def _sqlite_pi():
return pi
def _sqlite_power(x, y):
if x is None or y is None:
return None
return x**y
def _sqlite_radians(x):
if x is None:
return None
return radians(x)
def _sqlite_repeat(text, count):
if text is None or count is None:
return None
return text * count
def _sqlite_reverse(text):
if text is None:
return None
return text[::-1]
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]
def _sqlite_sha1(text):
if text is None:
return None
return sha1(text.encode()).hexdigest()
def _sqlite_sha224(text):
if text is None:
return None
return sha224(text.encode()).hexdigest()
def _sqlite_sha256(text):
if text is None:
return None
return sha256(text.encode()).hexdigest()
def _sqlite_sha384(text):
if text is None:
return None
return sha384(text.encode()).hexdigest()
def _sqlite_sha512(text):
if text is None:
return None
return sha512(text.encode()).hexdigest()
def _sqlite_sign(x):
if x is None:
return None
return (x > 0) - (x < 0)
def _sqlite_sin(x):
if x is None:
return None
return sin(x)
def _sqlite_sqrt(x):
if x is None:
return None
return sqrt(x)
def _sqlite_tan(x):
if x is None:
return None
return tan(x)
class ListAggregate(list):
step = list.append
class StdDevPop(ListAggregate):
finalize = statistics.pstdev
class StdDevSamp(ListAggregate):
finalize = statistics.stdev
class VarPop(ListAggregate):
finalize = statistics.pvariance
class VarSamp(ListAggregate):
finalize = statistics.variance