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gis: (1) fixed WKT admin bug

     (2) cleaned up GeometryField (moved SQL creation into field, index creation now on by default) 
     (3) now have exact lookup type, e.g., filter(geom='...') works


git-svn-id: http://code.djangoproject.com/svn/django/branches/gis@5336 bcc190cf-cafb-0310-a4f2-bffc1f526a37
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jbronn committed May 25, 2007
1 parent 58aa35e commit f84bb1b18f1502844c3e3b52cdb17f19bdc891b6
@@ -1,60 +1,78 @@
# The Django base Field class.
from django.db.models.fields import Field
-from django.contrib.gis.db.models.postgis import POSTGIS_TERMS
+from django.contrib.gis.db.models.postgis import POSTGIS_TERMS, quotename
from django.contrib.gis.oldforms import WKTField
from django.utils.functional import curry
-
-#TODO: add db.quotename.
-
-# Creates the SQL to add the model to the database.
-def _add_geom(geom, srid, style, model, field, dim=2):
- # Constructing the AddGeometryColumn(...) command -- the style
- # object is passed in from the management module and is used
- # to syntax highlight the command for 'sqlall'
- sql = style.SQL_KEYWORD('SELECT ') + \
- style.SQL_TABLE('AddGeometryColumn') + "('" + \
- style.SQL_TABLE(model) + "', '" + \
- style.SQL_FIELD(field) + "', " + \
- style.SQL_FIELD(str(srid)) + ", '" + \
- style.SQL_COLTYPE(geom) + "', " + \
- style.SQL_KEYWORD(str(dim)) + \
- ');'
- return sql
-
-# Creates an index for the given geometry.
-def _geom_index(geom, style, model, field,
- index_type='GIST',
- index_opts='GIST_GEOMETRY_OPS'):
- sql = style.SQL_KEYWORD('CREATE INDEX ') + \
- style.SQL_TABLE('"%s_%s_id"' % (model, field)) + \
- style.SQL_KEYWORD(' ON ') + \
- style.SQL_TABLE('"%s"' % model) + \
- style.SQL_KEYWORD(' USING ') + \
- style.SQL_COLTYPE(index_type) + ' ( ' + \
- style.SQL_FIELD('"%s"' % field) + ' ' + \
- style.SQL_KEYWORD(index_opts) + ' );'
- return sql
+from django.contrib.gis.geos import GEOSGeometry, GEOSException
class GeometryField(Field):
- "The base GIS field -- maps to the OpenGIS Geometry type."
+ "The base GIS field -- maps to the OpenGIS Specification Geometry type."
# The OpenGIS Geometry name.
_geom = 'GEOMETRY'
- def __init__(self, srid=4326, index=False, **kwargs):
- #TODO: SRID a standard, or specific to postgis?
- # Whether or not index this field, defaults to False
- # Why can't we just use db_index?
- # TODO: Move index creation (and kwarg lookup, and...)
- # into Field rather than core.management and db.models.query.
- self._index = index
+ def __init__(self, srid=4326, index=True, dim=2, **kwargs):
+ """The initialization function for geometry fields. Takes the following
+ as keyword arguments:
+
+ srid - The spatial reference system identifier. An OGC standard.
+ Defaults to 4326 (WGS84)
- # The SRID for the geometry, defaults to 4326.
+ index - Indicates whether to create a GiST index. Defaults to True.
+ Set this instead of 'db_index' for geographic fields since index
+ creation is different for geometry columns.
+
+ dim - The number of dimensions for this geometry. Defaults to 2.
+ """
+ self._index = index
self._srid = srid
+ self._dim = dim
+ super(GeometryField, self).__init__(**kwargs) # Calling the parent initializtion function
+
+ def _add_geom(self, style, db_table, field):
+ """Constructs the addition of the geometry to the table using the
+ AddGeometryColumn(...) PostGIS (and OGC standard) function.
+
+ Takes the style object (provides syntax highlighting) as well as the
+ database table and field. The dimensions can be specified via
+ the dim keyword as well.
+ """
+ sql = style.SQL_KEYWORD('SELECT ') + \
+ style.SQL_TABLE('AddGeometryColumn') + '(' + \
+ style.SQL_TABLE(quotename(db_table)) + ', ' + \
+ style.SQL_FIELD(quotename(field)) + ', ' + \
+ style.SQL_FIELD(str(self._srid)) + ', ' + \
+ style.SQL_COLTYPE(quotename(self._geom)) + ', ' + \
+ style.SQL_KEYWORD(str(self._dim)) + ');'
+ return sql
+
+ def _geom_index(self, style, db_table, field,
+ index_type='GIST', index_opts='GIST_GEOMETRY_OPS'):
+ "Creates a GiST index for this geometry field."
+ sql = style.SQL_KEYWORD('CREATE INDEX ') + \
+ style.SQL_TABLE(quotename('%s_%s_id' % (db_table, field), dbl=True)) + \
+ style.SQL_KEYWORD(' ON ') + \
+ style.SQL_TABLE(quotename(db_table, dbl=True)) + \
+ style.SQL_KEYWORD(' USING ') + \
+ style.SQL_COLTYPE(index_type) + ' ( ' + \
+ style.SQL_FIELD(quotename(field, dbl=True)) + ' ' + \
+ style.SQL_KEYWORD(index_opts) + ' );'
+ return sql
+
+ def _post_create_sql(self, style, db_table, field):
+ """Returns SQL that will be executed after the model has been
+ created. Geometry columns must be added after creation with the
+ PostGIS AddGeometryColumn() function."""
- # Calling the Field initialization function first
- super(GeometryField, self).__init__(**kwargs)
+ # Getting the AddGeometryColumn() SQL necessary to create a PostGIS
+ # geometry field.
+ post_sql = self._add_geom(style, db_table, field)
+ # If the user wants to index this data, then get the indexing SQL as well.
+ if self._index:
+ return '%s\n%s' % (post_sql, self._geom_index(style, db_table, field))
+ else:
+ return post_sql
def contribute_to_class(self, cls, name):
super(GeometryField, self).contribute_to_class(cls, name)
@@ -64,26 +82,10 @@ def contribute_to_class(self, cls, name):
setattr(cls, 'get_%s_wkt' % self.name, curry(cls._get_GEOM_wkt, field=self))
setattr(cls, 'get_%s_centroid' % self.name, curry(cls._get_GEOM_centroid, field=self))
setattr(cls, 'get_%s_area' % self.name, curry(cls._get_GEOM_area, field=self))
-
+
def get_internal_type(self):
return "NoField"
-
- def _post_create_sql(self, *args, **kwargs):
- """Returns SQL that will be executed after the model has been created. Geometry
- columns must be added after creation with the PostGIS AddGeometryColumn() function."""
-
- #TODO: clean up *args/**kwargs.
-
- # Getting the AddGeometryColumn() SQL necessary to create a PostGIS
- # geometry field.
- post_sql = _add_geom(self._geom, self._srid, *args, **kwargs)
-
- # If the user wants to index this data, then get the indexing SQL as well.
- if self._index:
- return '%s\n%s' % (post_sql, _geom_index(self._geom, *args, **kwargs))
- else:
- return post_sql
-
+
def get_db_prep_lookup(self, lookup_type, value):
"""Returns field's value prepared for database lookup; the SRID of the geometry is
included by default in these queries."""
@@ -27,6 +27,7 @@
# The "~=" operator is the "same as" operator. It tests actual geometric equality of two features. So if
# A and B are the same feature, vertex-by-vertex, the operator returns true.
'same_as' : '~= %s',
+ 'exact' : '~= %s',
# The "@" operator returns true if A's bounding box is completely contained by B's bounding box.
'contained' : '@ %s',
# The "~" operator returns true if A's bounding box completely contains B's bounding box.
@@ -50,6 +51,11 @@
'relate' : 'Relate',
}
+# The quotation used for postgis (uses single quotes).
+def quotename(value, dbl=False):
+ if dbl: return '"%s"' % value
+ else: return "'%s'" % value
+
# These are the PostGIS-customized QUERY_TERMS, combines both the operators
# and the geometry functions.
POSTGIS_TERMS = list(POSTGIS_OPERATORS.keys()) # Getting the operators first
@@ -6,7 +6,11 @@ class WKTField(LargeTextField):
def render(self, data):
# PostGIS uses EWKBHEX to store its values internally, converting
- # to WKT for the admin first.
- return super(WKTField, self).render(hex_to_wkt(data))
+ # to WKT for the admin first -- unless there's no data, then just
+ # pass None to LargeTextField's render.
+ if not data:
+ return super(WKTField, self).render(None)
+ else:
+ return super(WKTField, self).render(hex_to_wkt(data))

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