1 import cx_Oracle

     2 from django.db.backends.oracle.introspection import DatabaseIntrospection

     3 

     4 class OracleIntrospection(DatabaseIntrospection):

     5     # Associating any OBJECTVAR instances with GeometryField.  Of course,

     6     # this won't work right on Oracle objects that aren't MDSYS.SDO_GEOMETRY,

     7     # but it is the only object type supported within Django anyways.

     8     data_types_reverse = DatabaseIntrospection.data_types_reverse.copy()

     9     data_types_reverse[cx_Oracle.OBJECT] = 'GeometryField'

    10 

    11     def get_geometry_type(self, table_name, geo_col):

    12         cursor = self.connection.cursor()

    13         try:

    14             # Querying USER_SDO_GEOM_METADATA to get the SRID and dimension information.

    15             try:

    16                 cursor.execute('SELECT "DIMINFO", "SRID" FROM "USER_SDO_GEOM_METADATA" WHERE "TABLE_NAME"=%s AND "COLUMN_NAME"=%s',

    17                                (table_name.upper(), geo_col.upper()))

    18                 row = cursor.fetchone()

    19             except Exception, msg:

    20                 raise Exception('Could not find entry in USER_SDO_GEOM_METADATA corresponding to "%s"."%s"\n'

    21                                 'Error message: %s.' % (table_name, geo_col, msg))

    22 

    23             # TODO: Research way to find a more specific geometry field type for

    24             # the column's contents.

    25             field_type = 'GeometryField'

    26 

    27             # Getting the field parameters.

    28             field_params = {}

    29             dim, srid = row

    30             if srid != 4326:

    31                 field_params['srid'] = srid

    32             # Length of object array ( SDO_DIM_ARRAY ) is number of dimensions.

    33             dim = len(dim)

    34             if dim != 2:

    35                 field_params['dim'] = dim

    36         finally:

    37             cursor.close()

    38 

    39         return field_type, field_params