/django/contrib/gis/db/backends/spatialite/base.py
https://code.google.com/p/mango-py/ · Python · 79 lines · 60 code · 7 blank · 12 comment · 9 complexity · 12184437bed945ee9203338bf510e46a MD5 · raw file
- from ctypes.util import find_library
- from django.conf import settings
- from django.core.exceptions import ImproperlyConfigured
- from django.db.backends.sqlite3.base import (
- _sqlite_extract, _sqlite_date_trunc, _sqlite_regexp, _sqlite_format_dtdelta,
- connection_created, Database, DatabaseWrapper as SQLiteDatabaseWrapper,
- SQLiteCursorWrapper)
- from django.contrib.gis.db.backends.spatialite.client import SpatiaLiteClient
- from django.contrib.gis.db.backends.spatialite.creation import SpatiaLiteCreation
- from django.contrib.gis.db.backends.spatialite.introspection import SpatiaLiteIntrospection
- from django.contrib.gis.db.backends.spatialite.operations import SpatiaLiteOperations
- class DatabaseWrapper(SQLiteDatabaseWrapper):
- def __init__(self, *args, **kwargs):
- # Before we get too far, make sure pysqlite 2.5+ is installed.
- if Database.version_info < (2, 5, 0):
- raise ImproperlyConfigured('Only versions of pysqlite 2.5+ are '
- 'compatible with SpatiaLite and GeoDjango.')
- # Trying to find the location of the SpatiaLite library.
- # Here we are figuring out the path to the SpatiaLite library
- # (`libspatialite`). If it's not in the system library path (e.g., it
- # cannot be found by `ctypes.util.find_library`), then it may be set
- # manually in the settings via the `SPATIALITE_LIBRARY_PATH` setting.
- self.spatialite_lib = getattr(settings, 'SPATIALITE_LIBRARY_PATH',
- find_library('spatialite'))
- if not self.spatialite_lib:
- raise ImproperlyConfigured('Unable to locate the SpatiaLite library. '
- 'Make sure it is in your library path, or set '
- 'SPATIALITE_LIBRARY_PATH in your settings.'
- )
- super(DatabaseWrapper, self).__init__(*args, **kwargs)
- self.ops = SpatiaLiteOperations(self)
- self.client = SpatiaLiteClient(self)
- self.creation = SpatiaLiteCreation(self)
- self.introspection = SpatiaLiteIntrospection(self)
- def _cursor(self):
- if self.connection is None:
- ## The following is the same as in django.db.backends.sqlite3.base ##
- settings_dict = self.settings_dict
- if not settings_dict['NAME']:
- 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)
- self.connection.create_function("django_format_dtdelta", 5, _sqlite_format_dtdelta)
- connection_created.send(sender=self.__class__, connection=self)
- ## From here on, customized for GeoDjango ##
- # Enabling extension loading on the SQLite connection.
- try:
- self.connection.enable_load_extension(True)
- except AttributeError:
- raise ImproperlyConfigured('The pysqlite library does not support C extension loading. '
- 'Both SQLite and pysqlite must be configured to allow '
- 'the loading of extensions to use SpatiaLite.'
- )
- # Loading the SpatiaLite library extension on the connection, and returning
- # the created cursor.
- cur = self.connection.cursor(factory=SQLiteCursorWrapper)
- try:
- cur.execute("SELECT load_extension(%s)", (self.spatialite_lib,))
- except Exception, msg:
- raise ImproperlyConfigured('Unable to load the SpatiaLite library extension '
- '"%s" because: %s' % (self.spatialite_lib, msg))
- return cur
- else:
- return self.connection.cursor(factory=SQLiteCursorWrapper)