app/django/contrib/gis/db/backend/mysql/query.py
author Sverre Rabbelier <sverre@rabbelier.nl>
Mon, 07 Sep 2009 20:27:37 +0200
changeset 2878 cf4b80992451
parent 323 ff1a9aa48cfd
permissions -rw-r--r--
merge with wrong head
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
323
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
     1
"""
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
     2
 This module contains the spatial lookup types, and the `get_geo_where_clause`
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
     3
 routine for MySQL.
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
     4
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
     5
 Please note that MySQL only supports bounding box queries, also
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
     6
 known as MBRs (Minimum Bounding Rectangles).  Moreover, spatial
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
     7
 indices may only be used on MyISAM tables -- if you need 
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
     8
 transactions, take a look at PostGIS.
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
     9
"""
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    10
from django.db import connection
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    11
qn = connection.ops.quote_name
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    12
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    13
# To ease implementation, WKT is passed to/from MySQL.
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    14
GEOM_FROM_TEXT = 'GeomFromText'
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    15
GEOM_FROM_WKB = 'GeomFromWKB'
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    16
GEOM_SELECT = 'AsText(%s)'
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    17
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    18
# WARNING: MySQL is NOT compliant w/the OpenGIS specification and
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    19
# _every_ one of these lookup types is on the _bounding box_ only.
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    20
MYSQL_GIS_FUNCTIONS = {
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    21
    'bbcontains' : 'MBRContains', # For consistency w/PostGIS API
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    22
    'bboverlaps' : 'MBROverlaps', # .. ..
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    23
    'contained' : 'MBRWithin',    # .. ..
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    24
    'contains' : 'MBRContains',
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    25
    'disjoint' : 'MBRDisjoint',
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    26
    'equals' : 'MBREqual',
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    27
    'exact' : 'MBREqual',
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    28
    'intersects' : 'MBRIntersects',
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    29
    'overlaps' : 'MBROverlaps',
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    30
    'same_as' : 'MBREqual',
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    31
    'touches' : 'MBRTouches',
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    32
    'within' : 'MBRWithin',
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    33
    }
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    34
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    35
# This lookup type does not require a mapping.
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    36
MISC_TERMS = ['isnull']
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    37
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    38
# Assacceptable lookup types for Oracle spatial.
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    39
MYSQL_GIS_TERMS  = MYSQL_GIS_FUNCTIONS.keys()
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    40
MYSQL_GIS_TERMS += MISC_TERMS
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    41
MYSQL_GIS_TERMS = dict((term, None) for term in MYSQL_GIS_TERMS) # Making dictionary 
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    42
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    43
def get_geo_where_clause(table_alias, name, lookup_type, geo_annot):
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    44
    "Returns the SQL WHERE clause for use in MySQL spatial SQL construction."
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    45
    # Getting the quoted field as `geo_col`.
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    46
    geo_col = '%s.%s' % (qn(table_alias), qn(name))
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    47
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    48
    # See if a MySQL Geometry function matches the lookup type next
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    49
    lookup_info = MYSQL_GIS_FUNCTIONS.get(lookup_type, False)
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    50
    if lookup_info:
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    51
        return "%s(%s, %%s)" % (lookup_info, geo_col)
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    52
    
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    53
    # Handling 'isnull' lookup type
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    54
    # TODO: Is this needed because MySQL cannot handle NULL
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    55
    # geometries in its spatial indices.
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    56
    if lookup_type == 'isnull':
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    57
        return "%s IS %sNULL" % (geo_col, (not geo_annot.value and 'NOT ' or ''))
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    58
ff1a9aa48cfd Load ../vendor/django into trunk/app/django.
Pawel Solyga <Pawel.Solyga@gmail.com>
parents:
diff changeset
    59
    raise TypeError("Got invalid lookup_type: %s" % repr(lookup_type))