--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/app/django/contrib/gis/db/backend/mysql/query.py	Tue Oct 14 16:00:59 2008 +0000
@@ -0,0 +1,59 @@
+"""
+ This module contains the spatial lookup types, and the `get_geo_where_clause`
+ routine for MySQL.
+
+ Please note that MySQL only supports bounding box queries, also
+ known as MBRs (Minimum Bounding Rectangles).  Moreover, spatial
+ indices may only be used on MyISAM tables -- if you need 
+ transactions, take a look at PostGIS.
+"""
+from django.db import connection
+qn = connection.ops.quote_name
+
+# To ease implementation, WKT is passed to/from MySQL.
+GEOM_FROM_TEXT = 'GeomFromText'
+GEOM_FROM_WKB = 'GeomFromWKB'
+GEOM_SELECT = 'AsText(%s)'
+
+# WARNING: MySQL is NOT compliant w/the OpenGIS specification and
+# _every_ one of these lookup types is on the _bounding box_ only.
+MYSQL_GIS_FUNCTIONS = {
+    'bbcontains' : 'MBRContains', # For consistency w/PostGIS API
+    'bboverlaps' : 'MBROverlaps', # .. ..
+    'contained' : 'MBRWithin',    # .. ..
+    'contains' : 'MBRContains',
+    'disjoint' : 'MBRDisjoint',
+    'equals' : 'MBREqual',
+    'exact' : 'MBREqual',
+    'intersects' : 'MBRIntersects',
+    'overlaps' : 'MBROverlaps',
+    'same_as' : 'MBREqual',
+    'touches' : 'MBRTouches',
+    'within' : 'MBRWithin',
+    }
+
+# This lookup type does not require a mapping.
+MISC_TERMS = ['isnull']
+
+# Assacceptable lookup types for Oracle spatial.
+MYSQL_GIS_TERMS  = MYSQL_GIS_FUNCTIONS.keys()
+MYSQL_GIS_TERMS += MISC_TERMS
+MYSQL_GIS_TERMS = dict((term, None) for term in MYSQL_GIS_TERMS) # Making dictionary 
+
+def get_geo_where_clause(table_alias, name, lookup_type, geo_annot):
+    "Returns the SQL WHERE clause for use in MySQL spatial SQL construction."
+    # Getting the quoted field as `geo_col`.
+    geo_col = '%s.%s' % (qn(table_alias), qn(name))
+
+    # See if a MySQL Geometry function matches the lookup type next
+    lookup_info = MYSQL_GIS_FUNCTIONS.get(lookup_type, False)
+    if lookup_info:
+        return "%s(%s, %%s)" % (lookup_info, geo_col)
+    
+    # Handling 'isnull' lookup type
+    # TODO: Is this needed because MySQL cannot handle NULL
+    # geometries in its spatial indices.
+    if lookup_type == 'isnull':
+        return "%s IS %sNULL" % (geo_col, (not geo_annot.value and 'NOT ' or ''))
+
+    raise TypeError("Got invalid lookup_type: %s" % repr(lookup_type))