464 lines
17 KiB
Python
464 lines
17 KiB
Python
"""
|
|
SQLite3 backend for the sqlite3 module in the standard library.
|
|
"""
|
|
import decimal
|
|
import re
|
|
import warnings
|
|
from sqlite3 import dbapi2 as Database
|
|
|
|
import pytz
|
|
|
|
from django.core.exceptions import ImproperlyConfigured
|
|
from django.db import utils
|
|
from django.db.backends import utils as backend_utils
|
|
from django.db.backends.base.base import BaseDatabaseWrapper
|
|
from django.utils import timezone
|
|
from django.utils.dateparse import (
|
|
parse_date, parse_datetime, parse_duration, parse_time,
|
|
)
|
|
from django.utils.encoding import force_text
|
|
|
|
from .client import DatabaseClient # isort:skip
|
|
from .creation import DatabaseCreation # isort:skip
|
|
from .features import DatabaseFeatures # isort:skip
|
|
from .introspection import DatabaseIntrospection # isort:skip
|
|
from .operations import DatabaseOperations # isort:skip
|
|
from .schema import DatabaseSchemaEditor # isort:skip
|
|
|
|
|
|
def decoder(conv_func):
|
|
"""
|
|
Convert bytestrings from Python's sqlite3 interface to a regular string.
|
|
"""
|
|
return lambda s: conv_func(s.decode())
|
|
|
|
|
|
Database.register_converter("bool", decoder(lambda s: s == '1'))
|
|
Database.register_converter("time", decoder(parse_time))
|
|
Database.register_converter("date", decoder(parse_date))
|
|
Database.register_converter("datetime", decoder(parse_datetime))
|
|
Database.register_converter("timestamp", decoder(parse_datetime))
|
|
Database.register_converter("TIMESTAMP", decoder(parse_datetime))
|
|
Database.register_converter("decimal", decoder(backend_utils.typecast_decimal))
|
|
|
|
Database.register_adapter(decimal.Decimal, backend_utils.rev_typecast_decimal)
|
|
|
|
|
|
class DatabaseWrapper(BaseDatabaseWrapper):
|
|
vendor = 'sqlite'
|
|
# SQLite doesn't actually support most of these types, but it "does the right
|
|
# thing" given more verbose field definitions, so leave them as is so that
|
|
# schema inspection is more useful.
|
|
data_types = {
|
|
'AutoField': 'integer',
|
|
'BigAutoField': 'integer',
|
|
'BinaryField': 'BLOB',
|
|
'BooleanField': 'bool',
|
|
'CharField': 'varchar(%(max_length)s)',
|
|
'DateField': 'date',
|
|
'DateTimeField': 'datetime',
|
|
'DecimalField': 'decimal',
|
|
'DurationField': 'bigint',
|
|
'FileField': 'varchar(%(max_length)s)',
|
|
'FilePathField': 'varchar(%(max_length)s)',
|
|
'FloatField': 'real',
|
|
'IntegerField': 'integer',
|
|
'BigIntegerField': 'bigint',
|
|
'IPAddressField': 'char(15)',
|
|
'GenericIPAddressField': 'char(39)',
|
|
'NullBooleanField': 'bool',
|
|
'OneToOneField': 'integer',
|
|
'PositiveIntegerField': 'integer unsigned',
|
|
'PositiveSmallIntegerField': 'smallint unsigned',
|
|
'SlugField': 'varchar(%(max_length)s)',
|
|
'SmallIntegerField': 'smallint',
|
|
'TextField': 'text',
|
|
'TimeField': 'time',
|
|
'UUIDField': 'char(32)',
|
|
}
|
|
data_types_suffix = {
|
|
'AutoField': 'AUTOINCREMENT',
|
|
'BigAutoField': 'AUTOINCREMENT',
|
|
}
|
|
# SQLite requires LIKE statements to include an ESCAPE clause if the value
|
|
# being escaped has a percent or underscore in it.
|
|
# See http://www.sqlite.org/lang_expr.html for an explanation.
|
|
operators = {
|
|
'exact': '= %s',
|
|
'iexact': "LIKE %s ESCAPE '\\'",
|
|
'contains': "LIKE %s ESCAPE '\\'",
|
|
'icontains': "LIKE %s ESCAPE '\\'",
|
|
'regex': 'REGEXP %s',
|
|
'iregex': "REGEXP '(?i)' || %s",
|
|
'gt': '> %s',
|
|
'gte': '>= %s',
|
|
'lt': '< %s',
|
|
'lte': '<= %s',
|
|
'startswith': "LIKE %s ESCAPE '\\'",
|
|
'endswith': "LIKE %s ESCAPE '\\'",
|
|
'istartswith': "LIKE %s ESCAPE '\\'",
|
|
'iendswith': "LIKE %s ESCAPE '\\'",
|
|
}
|
|
|
|
# The patterns below are used to generate SQL pattern lookup clauses when
|
|
# the right-hand side of the lookup isn't a raw string (it might be an expression
|
|
# or the result of a bilateral transformation).
|
|
# In those cases, special characters for LIKE operators (e.g. \, *, _) should be
|
|
# escaped on database side.
|
|
#
|
|
# Note: we use str.format() here for readability as '%' is used as a wildcard for
|
|
# the LIKE operator.
|
|
pattern_esc = r"REPLACE(REPLACE(REPLACE({}, '\', '\\'), '%%', '\%%'), '_', '\_')"
|
|
pattern_ops = {
|
|
'contains': r"LIKE '%%' || {} || '%%' ESCAPE '\'",
|
|
'icontains': r"LIKE '%%' || UPPER({}) || '%%' ESCAPE '\'",
|
|
'startswith': r"LIKE {} || '%%' ESCAPE '\'",
|
|
'istartswith': r"LIKE UPPER({}) || '%%' ESCAPE '\'",
|
|
'endswith': r"LIKE '%%' || {} ESCAPE '\'",
|
|
'iendswith': r"LIKE '%%' || UPPER({}) ESCAPE '\'",
|
|
}
|
|
|
|
Database = Database
|
|
SchemaEditorClass = DatabaseSchemaEditor
|
|
# Classes instantiated in __init__().
|
|
client_class = DatabaseClient
|
|
creation_class = DatabaseCreation
|
|
features_class = DatabaseFeatures
|
|
introspection_class = DatabaseIntrospection
|
|
ops_class = DatabaseOperations
|
|
|
|
def get_connection_params(self):
|
|
settings_dict = self.settings_dict
|
|
if not settings_dict['NAME']:
|
|
raise ImproperlyConfigured(
|
|
"settings.DATABASES is improperly configured. "
|
|
"Please supply the NAME value.")
|
|
kwargs = {
|
|
'database': settings_dict['NAME'],
|
|
'detect_types': Database.PARSE_DECLTYPES | Database.PARSE_COLNAMES,
|
|
}
|
|
kwargs.update(settings_dict['OPTIONS'])
|
|
# Always allow the underlying SQLite connection to be shareable
|
|
# between multiple threads. The safe-guarding will be handled at a
|
|
# higher level by the `BaseDatabaseWrapper.allow_thread_sharing`
|
|
# property. This is necessary as the shareability is disabled by
|
|
# default in pysqlite and it cannot be changed once a connection is
|
|
# opened.
|
|
if 'check_same_thread' in kwargs and kwargs['check_same_thread']:
|
|
warnings.warn(
|
|
'The `check_same_thread` option was provided and set to '
|
|
'True. It will be overridden with False. Use the '
|
|
'`DatabaseWrapper.allow_thread_sharing` property instead '
|
|
'for controlling thread shareability.',
|
|
RuntimeWarning
|
|
)
|
|
kwargs.update({'check_same_thread': False})
|
|
if self.features.can_share_in_memory_db:
|
|
kwargs.update({'uri': True})
|
|
return kwargs
|
|
|
|
def get_new_connection(self, conn_params):
|
|
conn = Database.connect(**conn_params)
|
|
conn.create_function("django_date_extract", 2, _sqlite_date_extract)
|
|
conn.create_function("django_date_trunc", 2, _sqlite_date_trunc)
|
|
conn.create_function("django_datetime_cast_date", 2, _sqlite_datetime_cast_date)
|
|
conn.create_function("django_datetime_cast_time", 2, _sqlite_datetime_cast_time)
|
|
conn.create_function("django_datetime_extract", 3, _sqlite_datetime_extract)
|
|
conn.create_function("django_datetime_trunc", 3, _sqlite_datetime_trunc)
|
|
conn.create_function("django_time_extract", 2, _sqlite_time_extract)
|
|
conn.create_function("django_time_trunc", 2, _sqlite_time_trunc)
|
|
conn.create_function("django_time_diff", 2, _sqlite_time_diff)
|
|
conn.create_function("django_timestamp_diff", 2, _sqlite_timestamp_diff)
|
|
conn.create_function("regexp", 2, _sqlite_regexp)
|
|
conn.create_function("django_format_dtdelta", 3, _sqlite_format_dtdelta)
|
|
conn.create_function("django_power", 2, _sqlite_power)
|
|
return conn
|
|
|
|
def init_connection_state(self):
|
|
pass
|
|
|
|
def create_cursor(self, name=None):
|
|
return self.connection.cursor(factory=SQLiteCursorWrapper)
|
|
|
|
def close(self):
|
|
self.validate_thread_sharing()
|
|
# If database is in memory, closing the connection destroys the
|
|
# database. To prevent accidental data loss, ignore close requests on
|
|
# an in-memory db.
|
|
if not self.is_in_memory_db():
|
|
BaseDatabaseWrapper.close(self)
|
|
|
|
def _savepoint_allowed(self):
|
|
# Two conditions are required here:
|
|
# - A sufficiently recent version of SQLite to support savepoints,
|
|
# - Being in a transaction, which can only happen inside 'atomic'.
|
|
|
|
# When 'isolation_level' is not None, sqlite3 commits before each
|
|
# savepoint; it's a bug. When it is None, savepoints don't make sense
|
|
# because autocommit is enabled. The only exception is inside 'atomic'
|
|
# blocks. To work around that bug, on SQLite, 'atomic' starts a
|
|
# transaction explicitly rather than simply disable autocommit.
|
|
return self.features.uses_savepoints and self.in_atomic_block
|
|
|
|
def _set_autocommit(self, autocommit):
|
|
if autocommit:
|
|
level = None
|
|
else:
|
|
# sqlite3's internal default is ''. It's different from None.
|
|
# See Modules/_sqlite/connection.c.
|
|
level = ''
|
|
# 'isolation_level' is a misleading API.
|
|
# SQLite always runs at the SERIALIZABLE isolation level.
|
|
with self.wrap_database_errors:
|
|
self.connection.isolation_level = level
|
|
|
|
def check_constraints(self, table_names=None):
|
|
"""
|
|
Check each table name in `table_names` for rows with invalid foreign
|
|
key references. This method is intended to be used in conjunction with
|
|
`disable_constraint_checking()` and `enable_constraint_checking()`, to
|
|
determine if rows with invalid references were entered while constraint
|
|
checks were off.
|
|
|
|
Raise an IntegrityError on the first invalid foreign key reference
|
|
encountered (if any) and provide detailed information about the
|
|
invalid reference in the error message.
|
|
|
|
Backends can override this method if they can more directly apply
|
|
constraint checking (e.g. via "SET CONSTRAINTS ALL IMMEDIATE")
|
|
"""
|
|
cursor = self.cursor()
|
|
if table_names is None:
|
|
table_names = self.introspection.table_names(cursor)
|
|
for table_name in table_names:
|
|
primary_key_column_name = self.introspection.get_primary_key_column(cursor, table_name)
|
|
if not primary_key_column_name:
|
|
continue
|
|
key_columns = self.introspection.get_key_columns(cursor, table_name)
|
|
for column_name, referenced_table_name, referenced_column_name in key_columns:
|
|
cursor.execute(
|
|
"""
|
|
SELECT REFERRING.`%s`, REFERRING.`%s` FROM `%s` as REFERRING
|
|
LEFT JOIN `%s` as REFERRED
|
|
ON (REFERRING.`%s` = REFERRED.`%s`)
|
|
WHERE REFERRING.`%s` IS NOT NULL AND REFERRED.`%s` IS NULL
|
|
"""
|
|
% (
|
|
primary_key_column_name, column_name, table_name,
|
|
referenced_table_name, column_name, referenced_column_name,
|
|
column_name, referenced_column_name,
|
|
)
|
|
)
|
|
for bad_row in cursor.fetchall():
|
|
raise utils.IntegrityError(
|
|
"The row in table '%s' with primary key '%s' has an "
|
|
"invalid foreign key: %s.%s contains a value '%s' that "
|
|
"does not have a corresponding value in %s.%s." % (
|
|
table_name, bad_row[0], table_name, column_name,
|
|
bad_row[1], referenced_table_name, referenced_column_name,
|
|
)
|
|
)
|
|
|
|
def is_usable(self):
|
|
return True
|
|
|
|
def _start_transaction_under_autocommit(self):
|
|
"""
|
|
Start a transaction explicitly in autocommit mode.
|
|
|
|
Staying in autocommit mode works around a bug of sqlite3 that breaks
|
|
savepoints when autocommit is disabled.
|
|
"""
|
|
self.cursor().execute("BEGIN")
|
|
|
|
def is_in_memory_db(self):
|
|
return self.creation.is_in_memory_db(self.settings_dict['NAME'])
|
|
|
|
|
|
FORMAT_QMARK_REGEX = re.compile(r'(?<!%)%s')
|
|
|
|
|
|
class SQLiteCursorWrapper(Database.Cursor):
|
|
"""
|
|
Django uses "format" style placeholders, but pysqlite2 uses "qmark" style.
|
|
This fixes it -- but note that if you want to use a literal "%s" in a query,
|
|
you'll need to use "%%s".
|
|
"""
|
|
def execute(self, query, params=None):
|
|
if params is None:
|
|
return Database.Cursor.execute(self, query)
|
|
query = self.convert_query(query)
|
|
return Database.Cursor.execute(self, query, params)
|
|
|
|
def executemany(self, query, param_list):
|
|
query = self.convert_query(query)
|
|
return Database.Cursor.executemany(self, query, param_list)
|
|
|
|
def convert_query(self, query):
|
|
return FORMAT_QMARK_REGEX.sub('?', query).replace('%%', '%')
|
|
|
|
|
|
def _sqlite_date_extract(lookup_type, dt):
|
|
if dt is None:
|
|
return None
|
|
try:
|
|
dt = backend_utils.typecast_timestamp(dt)
|
|
except (ValueError, TypeError):
|
|
return None
|
|
if lookup_type == 'week_day':
|
|
return (dt.isoweekday() % 7) + 1
|
|
elif lookup_type == 'week':
|
|
return dt.isocalendar()[1]
|
|
else:
|
|
return getattr(dt, lookup_type)
|
|
|
|
|
|
def _sqlite_date_trunc(lookup_type, dt):
|
|
try:
|
|
dt = backend_utils.typecast_timestamp(dt)
|
|
except (ValueError, TypeError):
|
|
return None
|
|
if lookup_type == 'year':
|
|
return "%i-01-01" % dt.year
|
|
elif lookup_type == 'month':
|
|
return "%i-%02i-01" % (dt.year, dt.month)
|
|
elif lookup_type == 'day':
|
|
return "%i-%02i-%02i" % (dt.year, dt.month, dt.day)
|
|
|
|
|
|
def _sqlite_time_trunc(lookup_type, dt):
|
|
try:
|
|
dt = backend_utils.typecast_time(dt)
|
|
except (ValueError, TypeError):
|
|
return None
|
|
if lookup_type == 'hour':
|
|
return "%02i:00:00" % dt.hour
|
|
elif lookup_type == 'minute':
|
|
return "%02i:%02i:00" % (dt.hour, dt.minute)
|
|
elif lookup_type == 'second':
|
|
return "%02i:%02i:%02i" % (dt.hour, dt.minute, dt.second)
|
|
|
|
|
|
def _sqlite_datetime_parse(dt, tzname):
|
|
if dt is None:
|
|
return None
|
|
try:
|
|
dt = backend_utils.typecast_timestamp(dt)
|
|
except (ValueError, TypeError):
|
|
return None
|
|
if tzname is not None:
|
|
dt = timezone.localtime(dt, pytz.timezone(tzname))
|
|
return dt
|
|
|
|
|
|
def _sqlite_datetime_cast_date(dt, tzname):
|
|
dt = _sqlite_datetime_parse(dt, tzname)
|
|
if dt is None:
|
|
return None
|
|
return dt.date().isoformat()
|
|
|
|
|
|
def _sqlite_datetime_cast_time(dt, tzname):
|
|
dt = _sqlite_datetime_parse(dt, tzname)
|
|
if dt is None:
|
|
return None
|
|
return dt.time().isoformat()
|
|
|
|
|
|
def _sqlite_datetime_extract(lookup_type, dt, tzname):
|
|
dt = _sqlite_datetime_parse(dt, tzname)
|
|
if dt is None:
|
|
return None
|
|
if lookup_type == 'week_day':
|
|
return (dt.isoweekday() % 7) + 1
|
|
elif lookup_type == 'week':
|
|
return dt.isocalendar()[1]
|
|
else:
|
|
return getattr(dt, lookup_type)
|
|
|
|
|
|
def _sqlite_datetime_trunc(lookup_type, dt, tzname):
|
|
dt = _sqlite_datetime_parse(dt, tzname)
|
|
if dt is None:
|
|
return None
|
|
if lookup_type == 'year':
|
|
return "%i-01-01 00:00:00" % dt.year
|
|
elif lookup_type == 'month':
|
|
return "%i-%02i-01 00:00:00" % (dt.year, dt.month)
|
|
elif lookup_type == 'day':
|
|
return "%i-%02i-%02i 00:00:00" % (dt.year, dt.month, dt.day)
|
|
elif lookup_type == 'hour':
|
|
return "%i-%02i-%02i %02i:00:00" % (dt.year, dt.month, dt.day, dt.hour)
|
|
elif lookup_type == 'minute':
|
|
return "%i-%02i-%02i %02i:%02i:00" % (dt.year, dt.month, dt.day, dt.hour, dt.minute)
|
|
elif lookup_type == 'second':
|
|
return "%i-%02i-%02i %02i:%02i:%02i" % (dt.year, dt.month, dt.day, dt.hour, dt.minute, dt.second)
|
|
|
|
|
|
def _sqlite_time_extract(lookup_type, dt):
|
|
if dt is None:
|
|
return None
|
|
try:
|
|
dt = backend_utils.typecast_time(dt)
|
|
except (ValueError, TypeError):
|
|
return None
|
|
return getattr(dt, lookup_type)
|
|
|
|
|
|
def _sqlite_format_dtdelta(conn, lhs, rhs):
|
|
"""
|
|
LHS and RHS can be either:
|
|
- An integer number of microseconds
|
|
- A string representing a timedelta object
|
|
- A string representing a datetime
|
|
"""
|
|
try:
|
|
if isinstance(lhs, int):
|
|
lhs = str(decimal.Decimal(lhs) / decimal.Decimal(1000000))
|
|
real_lhs = parse_duration(lhs)
|
|
if real_lhs is None:
|
|
real_lhs = backend_utils.typecast_timestamp(lhs)
|
|
if isinstance(rhs, int):
|
|
rhs = str(decimal.Decimal(rhs) / decimal.Decimal(1000000))
|
|
real_rhs = parse_duration(rhs)
|
|
if real_rhs is None:
|
|
real_rhs = backend_utils.typecast_timestamp(rhs)
|
|
if conn.strip() == '+':
|
|
out = real_lhs + real_rhs
|
|
else:
|
|
out = real_lhs - real_rhs
|
|
except (ValueError, TypeError):
|
|
return None
|
|
# 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]"
|
|
return str(out)
|
|
|
|
|
|
def _sqlite_time_diff(lhs, rhs):
|
|
left = backend_utils.typecast_time(lhs)
|
|
right = backend_utils.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):
|
|
left = backend_utils.typecast_timestamp(lhs)
|
|
right = backend_utils.typecast_timestamp(rhs)
|
|
return (left - right).total_seconds() * 1000000
|
|
|
|
|
|
def _sqlite_regexp(re_pattern, re_string):
|
|
return bool(re.search(re_pattern, force_text(re_string))) if re_string is not None else False
|
|
|
|
|
|
def _sqlite_power(x, y):
|
|
return x ** y
|