Changes between Version 44 and Version 45 of GeoDjango

Timestamp:

Mar 25, 2007, 3:16:15 PM (17 years ago)

Author:

jbronn

Comment:

improved reference citing, and clarified Model & DB API docs

GeoDjango

@@ +1 @@
+= Contents =
 The [http://code.djangoproject.com/browser/django/branches/gis gis] branch intends to add a contrib app allowing for Geographic-enabled fields and queries.
-
-'''Table of Contents'''
  * [GeoDjango#Background Background]
  * [GeoDjango#FAQ FAQ]
@@ -186 +185 @@
 
 = Model API =
-== Field Keywords ==
- * Field keywords are used during model creation, for example:
-{{{
-class Zip(models.Model):
-  code = models.IntegerField()
-  poly = models.PolygonField(srid=-1, index=True)
-}}}
-
- * {{{srid}}}
-   * Sets the SRID of geometry to the value.  Defaults to 4326 (WGS84)
- * {{{index}}}
-   * If set to True, will create an index for the given geometry.
-   * '''Disabled.'''  Implemented, but there's a bug and won't allow syncdb to execute.
-
 == Fields ==
 
@@ -211 +196 @@
  * {{{GeometryCollectionField}}}
 
-== Creating a Geometry Object and Saving ==
+== Field Keywords ==
+ * Field keywords are used during model creation, for example:
+{{{
+from django.contrib.gis.db import models
+
+class Zip(models.Model):
+  code = models.IntegerField()
+  poly = models.PolygonField(srid=-1, index=True)
+}}}
+
+ * {{{srid}}}
+   * Sets the SRID of geometry to the value.  Defaults to 4326 (WGS84)
+ * {{{index}}}
+   * If set to True, will create an index for the given geometry.
+   * '''Disabled.'''  Implemented, but there's a bug and won't allow syncdb to execute.
+
+== Creating and Saving Models with Geometry Fields ==
 Here is an example of how to create a geometry object (assuming the {{{Zip}}} model example above):
 
@@ -222 +223 @@
 Geometries are represented as '''strings''' in either of the formats WKT (Well Known Text) or HEXEWKB (PostGIS specific, essentially a WKB geometry in hexadecimal).  For example:
  * WKT Polygon: {{{'POLYGON(( 10 10, 10 20, 20 20, 20 15, 10 10))'}}}
+   * ''See'' Open GIS Consortium, Inc., ''[http://portal.opengeospatial.org/files/?artifact_id=829&ei=Z5oGRv6aCZ-IwQKh2LXwAw&usg=__4YgoHsbqjocl8Z01SwMAyN84aW0=&sig2=4DpSpm83ZDEIBKSivWcYGQ OpenGIS Simple Feature Specification For SQL]'', Document 99-049 (May 5, 1999), at  Ch. 3.2.5 (SQL Textual Representation of Geometry, pg. 53).
  * HEXEWKB Polygon: '{{{0103000000010000000 ... 00000000000002440'}}}
-
-'''References:'''
- * ''See'' Open GIS Consortium, Inc., ''[http://portal.opengeospatial.org/files/?artifact_id=829&ei=Z5oGRv6aCZ-IwQKh2LXwAw&usg=__4YgoHsbqjocl8Z01SwMAyN84aW0=&sig2=4DpSpm83ZDEIBKSivWcYGQ OpenGIS Simple Feature Specification For SQL]'', Document 99-049 (May 5, 1999), at  Ch. 3.2.5 (SQL Textual Representation of Geometry, pg. 53).
- * ''See also'' [http://postgis.refractions.net/docs/ch04.html#id2904792 "PostGIS EWKB, EWKT and Canonical Forms"], PostGIS documentation at Ch. 4.1.2.
+   * ''See'' [http://postgis.refractions.net/docs/ch04.html#id2904792 "PostGIS EWKB, EWKT and Canonical Forms"], PostGIS documentation at Ch. 4.1.2. 
 
 = Database API =
+
+'''Note:''' The following database lookup types can only be used with {{{geo_filter()}}}.  All geographic queries are done with {{{geo_filter()}}} and {{{geo_exclude()}}}, thus separating the normal database API lookups from geographic-specific field queries.  However chains containing both {{{filter}}} and {{{geo_filter}}} may still be used.  Thus, geographic queries take the following form (assuming the {{{Zip}}} model used in the [GeoDjango#ModelAPI Model API] section):
+
+{{{
+>>> qs = Zip.objects.geo_filter(<Zip geo field A>__<geo lookup type>=<geo string B>)
+>>> qs = Zip.objects.geo_exclude(...)
+}}}
 
 == PostGIS Operator Field Lookup Types ==
@@ -272 +278 @@
 
 == PostGIS GEOS Function Field Lookup Types ==
- * ''See generally'' [http://postgis.refractions.net/docs/ch06.html#id2615853 "Geometry Relationship Functions", PostGIS Documentation at Ch. 6.1.2].  This documentation will be updated completely with the content from the aforementioned PostGIS docs.
+ * ''See generally'' [http://postgis.refractions.net/docs/ch06.html#id2615853 "Geometry Relationship Functions", PostGIS Documentation at Ch. 6.1.2].    
+ * This documentation will be updated completely with the content from the aforementioned PostGIS docs.
  * {{{distance}}}
    * Return the cartesian distance between two geometries in projected units.