--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/web/lib/django/contrib/gis/db/backend/spatialite/field.py Wed Jan 20 00:34:04 2010 +0100
@@ -0,0 +1,82 @@
+from django.db.models.fields import Field # Django base Field class
+
+# Quotename & geographic quotename, respectively
+from django.db import connection
+qn = connection.ops.quote_name
+from django.contrib.gis.db.backend.util import gqn
+from django.contrib.gis.db.backend.spatialite.query import GEOM_FROM_TEXT, TRANSFORM
+
+class SpatiaLiteField(Field):
+ """
+ The backend-specific geographic field for SpatiaLite.
+ """
+
+ def _add_geom(self, style, db_table):
+ """
+ Constructs the addition of the geometry to the table using the
+ AddGeometryColumn(...) OpenGIS stored procedure.
+
+ Takes the style object (provides syntax highlighting) and the
+ database table as parameters.
+ """
+ sql = (style.SQL_KEYWORD('SELECT ') +
+ style.SQL_TABLE('AddGeometryColumn') + '(' +
+ style.SQL_TABLE(gqn(db_table)) + ', ' +
+ style.SQL_FIELD(gqn(self.column)) + ', ' +
+ style.SQL_FIELD(str(self.srid)) + ', ' +
+ style.SQL_COLTYPE(gqn(self.geom_type)) + ', ' +
+ style.SQL_KEYWORD(str(self.dim)) + ', ' +
+ style.SQL_KEYWORD(str(int(not self.null))) +
+ ');')
+ return sql
+
+ def _geom_index(self, style, db_table):
+ "Creates a spatial index for this geometry field."
+ sql = (style.SQL_KEYWORD('SELECT ') +
+ style.SQL_TABLE('CreateSpatialIndex') + '(' +
+ style.SQL_TABLE(gqn(db_table)) + ', ' +
+ style.SQL_FIELD(gqn(self.column)) + ');')
+ return sql
+
+ def post_create_sql(self, style, db_table):
+ """
+ Returns SQL that will be executed after the model has been
+ created. Geometry columns must be added after creation with the
+ OpenGIS AddGeometryColumn() function.
+ """
+ # Getting the AddGeometryColumn() SQL necessary to create a OpenGIS
+ # geometry field.
+ post_sql = self._add_geom(style, db_table)
+
+ # If the user wants to index this data, then get the indexing SQL as well.
+ if self.spatial_index:
+ return (post_sql, self._geom_index(style, db_table))
+ else:
+ return (post_sql,)
+
+ def _post_delete_sql(self, style, db_table):
+ "Drops the geometry column."
+ sql = (style.SQL_KEYWORD('SELECT ') +
+ style.SQL_KEYWORD('DropGeometryColumn') + '(' +
+ style.SQL_TABLE(gqn(db_table)) + ', ' +
+ style.SQL_FIELD(gqn(self.column)) + ');')
+ return sql
+
+ def db_type(self):
+ """
+ SpatiaLite geometry columns are added by stored procedures;
+ should be None.
+ """
+ return None
+
+ def get_placeholder(self, value):
+ """
+ Provides a proper substitution value for Geometries that are not in the
+ SRID of the field. Specifically, this routine will substitute in the
+ Transform() and GeomFromText() function call(s).
+ """
+ if value is None or value.srid == self.srid:
+ return '%s(%%s,%s)' % (GEOM_FROM_TEXT, self.srid)
+ else:
+ # Adding Transform() to the SQL placeholder.
+ return '%s(%s(%%s,%s), %s)' % (TRANSFORM, GEOM_FROM_TEXT, value.srid, self.srid)