web/lib/django/contrib/gis/db/backends/oracle/operations.py
changeset 29 cc9b7e14412b
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/web/lib/django/contrib/gis/db/backends/oracle/operations.py	Tue May 25 02:43:45 2010 +0200
@@ -0,0 +1,293 @@
+"""
+ This module contains the spatial lookup types, and the `get_geo_where_clause`
+ routine for Oracle Spatial.
+
+ Please note that WKT support is broken on the XE version, and thus
+ this backend will not work on such platforms.  Specifically, XE lacks
+ support for an internal JVM, and Java libraries are required to use
+ the WKT constructors.
+"""
+import re
+from decimal import Decimal
+
+from django.db.backends.oracle.base import DatabaseOperations
+from django.contrib.gis.db.backends.base import BaseSpatialOperations
+from django.contrib.gis.db.backends.oracle.adapter import OracleSpatialAdapter
+from django.contrib.gis.db.backends.util import SpatialFunction
+from django.contrib.gis.geometry.backend import Geometry
+from django.contrib.gis.measure import Distance
+
+class SDOOperation(SpatialFunction):
+    "Base class for SDO* Oracle operations."
+    sql_template = "%(function)s(%(geo_col)s, %(geometry)s) %(operator)s '%(result)s'"
+
+    def __init__(self, func, **kwargs):
+        kwargs.setdefault('operator', '=')
+        kwargs.setdefault('result', 'TRUE')
+        super(SDOOperation, self).__init__(func, **kwargs)
+
+class SDODistance(SpatialFunction):
+    "Class for Distance queries."
+    sql_template = ('%(function)s(%(geo_col)s, %(geometry)s, %(tolerance)s) '
+                    '%(operator)s %(result)s')
+    dist_func = 'SDO_GEOM.SDO_DISTANCE'
+    def __init__(self, op, tolerance=0.05):
+        super(SDODistance, self).__init__(self.dist_func,
+                                          tolerance=tolerance,
+                                          operator=op, result='%s')
+
+class SDODWithin(SpatialFunction):
+    dwithin_func = 'SDO_WITHIN_DISTANCE'
+    sql_template = "%(function)s(%(geo_col)s, %(geometry)s, %%s) = 'TRUE'"
+    def __init__(self):
+        super(SDODWithin, self).__init__(self.dwithin_func)
+
+class SDOGeomRelate(SpatialFunction):
+    "Class for using SDO_GEOM.RELATE."
+    relate_func = 'SDO_GEOM.RELATE'
+    sql_template = ("%(function)s(%(geo_col)s, '%(mask)s', %(geometry)s, "
+                    "%(tolerance)s) %(operator)s '%(mask)s'")
+    def __init__(self, mask, tolerance=0.05):
+        # SDO_GEOM.RELATE(...) has a peculiar argument order: column, mask, geom, tolerance.
+        # Moreover, the runction result is the mask (e.g., 'DISJOINT' instead of 'TRUE').
+        super(SDOGeomRelate, self).__init__(self.relate_func, operator='=',
+                                            mask=mask, tolerance=tolerance)
+
+class SDORelate(SpatialFunction):
+    "Class for using SDO_RELATE."
+    masks = 'TOUCH|OVERLAPBDYDISJOINT|OVERLAPBDYINTERSECT|EQUAL|INSIDE|COVEREDBY|CONTAINS|COVERS|ANYINTERACT|ON'
+    mask_regex = re.compile(r'^(%s)(\+(%s))*$' % (masks, masks), re.I)
+    sql_template = "%(function)s(%(geo_col)s, %(geometry)s, 'mask=%(mask)s') = 'TRUE'"
+    relate_func = 'SDO_RELATE'
+    def __init__(self, mask):
+        if not self.mask_regex.match(mask):
+            raise ValueError('Invalid %s mask: "%s"' % (self.relate_func, mask))
+        super(SDORelate, self).__init__(self.relate_func, mask=mask)
+
+# Valid distance types and substitutions
+dtypes = (Decimal, Distance, float, int, long)
+
+class OracleOperations(DatabaseOperations, BaseSpatialOperations):
+    compiler_module = "django.contrib.gis.db.backends.oracle.compiler"
+
+    name = 'oracle'
+    oracle = True
+    valid_aggregates = dict([(a, None) for a in ('Union', 'Extent')])
+
+    Adapter = OracleSpatialAdapter
+    Adaptor = Adapter # Backwards-compatibility alias.
+
+    area = 'SDO_GEOM.SDO_AREA'
+    gml= 'SDO_UTIL.TO_GMLGEOMETRY'
+    centroid = 'SDO_GEOM.SDO_CENTROID'
+    difference = 'SDO_GEOM.SDO_DIFFERENCE'
+    distance = 'SDO_GEOM.SDO_DISTANCE'
+    extent= 'SDO_AGGR_MBR'
+    intersection= 'SDO_GEOM.SDO_INTERSECTION'
+    length = 'SDO_GEOM.SDO_LENGTH'
+    num_geom = 'SDO_UTIL.GETNUMELEM'
+    num_points = 'SDO_UTIL.GETNUMVERTICES'
+    perimeter = length
+    point_on_surface = 'SDO_GEOM.SDO_POINTONSURFACE'
+    reverse = 'SDO_UTIL.REVERSE_LINESTRING'
+    sym_difference = 'SDO_GEOM.SDO_XOR'
+    transform = 'SDO_CS.TRANSFORM'
+    union = 'SDO_GEOM.SDO_UNION'
+    unionagg = 'SDO_AGGR_UNION'
+
+    # We want to get SDO Geometries as WKT because it is much easier to
+    # instantiate GEOS proxies from WKT than SDO_GEOMETRY(...) strings.
+    # However, this adversely affects performance (i.e., Java is called
+    # to convert to WKT on every query).  If someone wishes to write a
+    # SDO_GEOMETRY(...) parser in Python, let me know =)
+    select = 'SDO_UTIL.TO_WKTGEOMETRY(%s)'
+
+    distance_functions = {
+        'distance_gt' : (SDODistance('>'), dtypes),
+        'distance_gte' : (SDODistance('>='), dtypes),
+        'distance_lt' : (SDODistance('<'), dtypes),
+        'distance_lte' : (SDODistance('<='), dtypes),
+        'dwithin' : (SDODWithin(), dtypes),
+        }
+
+    geometry_functions = {
+        'contains' : SDOOperation('SDO_CONTAINS'),
+        'coveredby' : SDOOperation('SDO_COVEREDBY'),
+        'covers' : SDOOperation('SDO_COVERS'),
+        'disjoint' : SDOGeomRelate('DISJOINT'),
+        'intersects' : SDOOperation('SDO_OVERLAPBDYINTERSECT'), # TODO: Is this really the same as ST_Intersects()?
+        'equals' : SDOOperation('SDO_EQUAL'),
+        'exact' : SDOOperation('SDO_EQUAL'),
+        'overlaps' : SDOOperation('SDO_OVERLAPS'),
+        'same_as' : SDOOperation('SDO_EQUAL'),
+        'relate' : (SDORelate, basestring), # Oracle uses a different syntax, e.g., 'mask=inside+touch'
+        'touches' : SDOOperation('SDO_TOUCH'),
+        'within' : SDOOperation('SDO_INSIDE'),
+        }
+    geometry_functions.update(distance_functions)
+
+    gis_terms = ['isnull']
+    gis_terms += geometry_functions.keys()
+    gis_terms = dict([(term, None) for term in gis_terms])
+
+    truncate_params = {'relate' : None}
+
+    def __init__(self, connection):
+        super(OracleOperations, self).__init__()
+        self.connection = connection
+
+    def convert_extent(self, clob):
+        if clob:
+            # Generally, Oracle returns a polygon for the extent -- however,
+            # it can return a single point if there's only one Point in the
+            # table.
+            ext_geom = Geometry(clob.read())
+            gtype = str(ext_geom.geom_type)
+            if gtype == 'Polygon':
+                # Construct the 4-tuple from the coordinates in the polygon.
+                shell = ext_geom.shell
+                ll, ur = shell[0][:2], shell[2][:2]
+            elif gtype == 'Point':
+                ll = ext_geom.coords[:2]
+                ur = ll
+            else:
+                raise Exception('Unexpected geometry type returned for extent: %s' % gtype)
+            xmin, ymin = ll
+            xmax, ymax = ur
+            return (xmin, ymin, xmax, ymax)
+        else:
+            return None
+
+    def convert_geom(self, clob, geo_field):
+        if clob:
+            return Geometry(clob.read(), geo_field.srid)
+        else:
+            return None
+
+    def geo_db_type(self, f):
+        """
+        Returns the geometry database type for Oracle.  Unlike other spatial
+        backends, no stored procedure is necessary and it's the same for all
+        geometry types.
+        """
+        return 'MDSYS.SDO_GEOMETRY'
+
+    def get_distance(self, f, value, lookup_type):
+        """
+        Returns the distance parameters given the value and the lookup type.
+        On Oracle, geometry columns with a geodetic coordinate system behave
+        implicitly like a geography column, and thus meters will be used as
+        the distance parameter on them.
+        """
+        if not value:
+            return []
+        value = value[0]
+        if isinstance(value, Distance):
+            if f.geodetic(self.connection):
+                dist_param = value.m
+            else:
+                dist_param = getattr(value, Distance.unit_attname(f.units_name(self.connection)))
+        else:
+            dist_param = value
+
+        # dwithin lookups on oracle require a special string parameter
+        # that starts with "distance=".
+        if lookup_type == 'dwithin':
+            dist_param = 'distance=%s' % dist_param
+
+        return [dist_param]
+
+    def get_geom_placeholder(self, f, value):
+        """
+        Provides a proper substitution value for Geometries that are not in the
+        SRID of the field.  Specifically, this routine will substitute in the
+        SDO_CS.TRANSFORM() function call.
+        """
+        if value is None:
+            return 'NULL'
+
+        def transform_value(val, srid):
+            return val.srid != srid
+
+        if hasattr(value, 'expression'):
+            if transform_value(value, f.srid):
+                placeholder = '%s(%%s, %s)' % (self.transform, f.srid)
+            else:
+                placeholder = '%s'
+            # No geometry value used for F expression, substitue in
+            # the column name instead.
+            return placeholder % '%s.%s' % tuple(map(self.quote_name, value.cols[value.expression]))
+        else:
+            if transform_value(value, f.srid):
+                return '%s(SDO_GEOMETRY(%%s, %s), %s)' % (self.transform, value.srid, f.srid)
+            else:
+                return 'SDO_GEOMETRY(%%s, %s)' % f.srid
+
+    def spatial_lookup_sql(self, lvalue, lookup_type, value, field, qn):
+        "Returns the SQL WHERE clause for use in Oracle spatial SQL construction."
+        alias, col, db_type = lvalue
+
+        # Getting the quoted table name as `geo_col`.
+        geo_col = '%s.%s' % (qn(alias), qn(col))
+
+        # See if a Oracle Geometry function matches the lookup type next
+        lookup_info = self.geometry_functions.get(lookup_type, False)
+        if lookup_info:
+            # Lookup types that are tuples take tuple arguments, e.g., 'relate' and
+            # 'dwithin' lookup types.
+            if isinstance(lookup_info, tuple):
+                # First element of tuple is lookup type, second element is the type
+                # of the expected argument (e.g., str, float)
+                sdo_op, arg_type = lookup_info
+                geom = value[0]
+
+                # Ensuring that a tuple _value_ was passed in from the user
+                if not isinstance(value, tuple):
+                    raise ValueError('Tuple required for `%s` lookup type.' % lookup_type)
+                if len(value) != 2:
+                    raise ValueError('2-element tuple required for %s lookup type.' % lookup_type)
+
+                # Ensuring the argument type matches what we expect.
+                if not isinstance(value[1], arg_type):
+                    raise ValueError('Argument type should be %s, got %s instead.' % (arg_type, type(value[1])))
+
+                if lookup_type == 'relate':
+                    # The SDORelate class handles construction for these queries,
+                    # and verifies the mask argument.
+                    return sdo_op(value[1]).as_sql(geo_col, self.get_geom_placeholder(field, geom))
+                else:
+                    # Otherwise, just call the `as_sql` method on the SDOOperation instance.
+                    return sdo_op.as_sql(geo_col, self.get_geom_placeholder(field, geom))
+            else:
+                # Lookup info is a SDOOperation instance, whose `as_sql` method returns
+                # the SQL necessary for the geometry function call. For example:
+                #  SDO_CONTAINS("geoapp_country"."poly", SDO_GEOMTRY('POINT(5 23)', 4326)) = 'TRUE'
+                return lookup_info.as_sql(geo_col, self.get_geom_placeholder(field, value))
+        elif lookup_type == 'isnull':
+            # Handling 'isnull' lookup type
+            return "%s IS %sNULL" % (geo_col, (not value and 'NOT ' or ''))
+
+        raise TypeError("Got invalid lookup_type: %s" % repr(lookup_type))
+
+    def spatial_aggregate_sql(self, agg):
+        """
+        Returns the spatial aggregate SQL template and function for the
+        given Aggregate instance.
+        """
+        agg_name = agg.__class__.__name__.lower()
+        if agg_name == 'union' : agg_name += 'agg'
+        if agg.is_extent:
+            sql_template = '%(function)s(%(field)s)'
+        else:
+            sql_template = '%(function)s(SDOAGGRTYPE(%(field)s,%(tolerance)s))'
+        sql_function = getattr(self, agg_name)
+        return self.select % sql_template, sql_function
+
+    # Routines for getting the OGC-compliant models.
+    def geometry_columns(self):
+        from django.contrib.gis.db.backends.oracle.models import GeometryColumns
+        return GeometryColumns
+
+    def spatial_ref_sys(self):
+        from django.contrib.gis.db.backends.oracle.models import SpatialRefSys
+        return SpatialRefSys