diff -r 000000000000 -r 0d40e90630ef web/lib/django/contrib/gis/db/backend/spatialite/field.py --- /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)