"""
SQLite3 backend for django.
Python 2.3 and 2.4 require pysqlite2 (http://pysqlite.org/).
Python 2.5 and later can use a pysqlite2 module or the sqlite3 module in the
standard library.
"""
import re
import sys
from django.db import utils
from django.db.backends import *
from django.db.backends.signals import connection_created
from django.db.backends.sqlite3.client import DatabaseClient
from django.db.backends.sqlite3.creation import DatabaseCreation
from django.db.backends.sqlite3.introspection import DatabaseIntrospection
from django.utils.safestring import SafeString
try:
try:
from pysqlite2 import dbapi2
except ImportError, e1:
from sqlite3 import dbapi2
except ImportError, exc:
import sys
from django.core.exceptions import ImproperlyConfigured
if sys.version_info < (2, 5, 0):
module = 'pysqlite2 module'
exc = e1
else:
module = 'either pysqlite2 or sqlite3 modules (tried in that order)'
raise ImproperlyConfigured("Error loading %s: %s" % (module, exc))
DatabaseError = Database.DatabaseError
IntegrityError = Database.IntegrityError
Database.register_converter("bool", lambda s: str(s) == '1')
Database.register_converter("time", util.typecast_time)
Database.register_converter("date", util.typecast_date)
Database.register_converter("datetime", util.typecast_timestamp)
Database.register_converter("timestamp", util.typecast_timestamp)
Database.register_converter("TIMESTAMP", util.typecast_timestamp)
Database.register_converter("decimal", util.typecast_decimal)
Database.register_adapter(decimal.Decimal, util.rev_typecast_decimal)
if Database.version_info >= (2,4,1):
# Starting in 2.4.1, the str type is not accepted anymore, therefore,
# we convert all str objects to Unicode
# As registering a adapter for a primitive type causes a small
# slow-down, this adapter is only registered for sqlite3 versions
# needing it.
Database.register_adapter(str, lambda s:s.decode('utf-8'))
Database.register_adapter(SafeString, lambda s:s.decode('utf-8'))
class DatabaseFeatures(BaseDatabaseFeatures):
# SQLite cannot handle us only partially reading from a cursor's result set
# and then writing the same rows to the database in another cursor. This
# setting ensures we always read result sets fully into memory all in one
# go.
can_use_chunked_reads = False
class DatabaseOperations(BaseDatabaseOperations):
def date_extract_sql(self, lookup_type, field_name):
# sqlite doesn't support extract, so we fake it with the user-defined
# function django_extract that's registered in connect(). Note that
# single quotes are used because this is a string (and could otherwise
# cause a collision with a field name).
return "django_extract('%s', %s)" % (lookup_type.lower(), field_name)
def date_trunc_sql(self, lookup_type, field_name):
# sqlite doesn't support DATE_TRUNC, so we fake it with a user-defined
# function django_date_trunc that's registered in connect(). Note that
# single quotes are used because this is a string (and could otherwise
# cause a collision with a field name).
return "django_date_trunc('%s', %s)" % (lookup_type.lower(), field_name)
def drop_foreignkey_sql(self):
return ""
def pk_default_value(self):
return 'NULL'
def quote_name(self, name):
if name.startswith('"') and name.endswith('"'):
return name # Quoting once is enough.
return '"%s"' % name
def no_limit_value(self):
return -1
def sql_flush(self, style, tables, sequences):
# NB: The generated SQL below is specific to SQLite
# Note: The DELETE FROM... SQL generated below works for SQLite databases
# because constraints don't exist
sql = ['%s %s %s;' % \
(style.SQL_KEYWORD('DELETE'),
style.SQL_KEYWORD('FROM'),
style.SQL_FIELD(self.quote_name(table))
) for table in tables]
# Note: No requirement for reset of auto-incremented indices (cf. other
# sql_flush() implementations). Just return SQL at this point
return sql
def year_lookup_bounds(self, value):
first = '%s-01-01'
second = '%s-12-31 23:59:59.999999'
return [first % value, second % value]
def convert_values(self, value, field):
"""SQLite returns floats when it should be returning decimals,
and gets dates and datetimes wrong.
For consistency with other backends, coerce when required.
"""
internal_type = field.get_internal_type()
if internal_type == 'DecimalField':
return util.typecast_decimal(field.format_number(value))
elif internal_type and internal_type.endswith('IntegerField') or internal_type == 'AutoField':
return int(value)
elif internal_type == 'DateField':
return util.typecast_date(value)
elif internal_type == 'DateTimeField':
return util.typecast_timestamp(value)
elif internal_type == 'TimeField':
return util.typecast_time(value)
# No field, or the field isn't known to be a decimal or integer
return value
class DatabaseWrapper(BaseDatabaseWrapper):
# 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 '\\'",
}
def __init__(self, *args, **kwargs):
super(DatabaseWrapper, self).__init__(*args, **kwargs)
self.features = DatabaseFeatures()
self.ops = DatabaseOperations()
self.client = DatabaseClient(self)
self.creation = DatabaseCreation(self)
self.introspection = DatabaseIntrospection(self)
self.validation = BaseDatabaseValidation(self)
def _cursor(self):
if self.connection is None:
settings_dict = self.settings_dict
if not settings_dict['NAME']:
from django.core.exceptions import ImproperlyConfigured
raise ImproperlyConfigured("Please fill out the database NAME in the settings module before using the database.")
kwargs = {
'database': settings_dict['NAME'],
'detect_types': Database.PARSE_DECLTYPES | Database.PARSE_COLNAMES,
}
kwargs.update(settings_dict['OPTIONS'])
self.connection = Database.connect(**kwargs)
# Register extract, date_trunc, and regexp functions.
self.connection.create_function("django_extract", 2, _sqlite_extract)
self.connection.create_function("django_date_trunc", 2, _sqlite_date_trunc)
self.connection.create_function("regexp", 2, _sqlite_regexp)
connection_created.send(sender=self.__class__)
return self.connection.cursor(factory=SQLiteCursorWrapper)
def close(self):
# 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 self.settings_dict['NAME'] != ":memory:":
BaseDatabaseWrapper.close(self)
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=()):
query = self.convert_query(query)
try:
return Database.Cursor.execute(self, query, params)
except Database.IntegrityError, e:
raise utils.IntegrityError, utils.IntegrityError(*tuple(e)), sys.exc_info()[2]
except Database.DatabaseError, e:
raise utils.DatabaseError, utils.DatabaseError(*tuple(e)), sys.exc_info()[2]
def executemany(self, query, param_list):
query = self.convert_query(query)
try:
return Database.Cursor.executemany(self, query, param_list)
except Database.IntegrityError, e:
raise utils.IntegrityError, utils.IntegrityError(*tuple(e)), sys.exc_info()[2]
except Database.DatabaseError, e:
raise utils.DatabaseError, utils.DatabaseError(*tuple(e)), sys.exc_info()[2]
def convert_query(self, query):
return FORMAT_QMARK_REGEX.sub('?', query).replace('%%','%')
def _sqlite_extract(lookup_type, dt):
if dt is None:
return None
try:
dt = util.typecast_timestamp(dt)
except (ValueError, TypeError):
return None
if lookup_type == 'week_day':
return (dt.isoweekday() % 7) + 1
else:
return getattr(dt, lookup_type)
def _sqlite_date_trunc(lookup_type, dt):
try:
dt = util.typecast_timestamp(dt)
except (ValueError, TypeError):
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)
def _sqlite_regexp(re_pattern, re_string):
import re
try:
return bool(re.search(re_pattern, re_string))
except:
return False
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