1 from django.db.backends.mysql.base import DatabaseOperations

     2 

     3 from django.contrib.gis.db.backends.adapter import WKTAdapter

     4 from django.contrib.gis.db.backends.base import BaseSpatialOperations

     5 

     6 class MySQLOperations(DatabaseOperations, BaseSpatialOperations):

     7 

     8     compiler_module = 'django.contrib.gis.db.models.sql.compiler'

     9     mysql = True

    10     name = 'mysql'

    11     select = 'AsText(%s)'

    12     from_wkb = 'GeomFromWKB'

    13     from_text = 'GeomFromText'

    14 

    15     Adapter = WKTAdapter

    16     Adaptor = Adapter # Backwards-compatibility alias.

    17 

    18     geometry_functions = {

    19         'bbcontains' : 'MBRContains', # For consistency w/PostGIS API

    20         'bboverlaps' : 'MBROverlaps', # .. ..

    21         'contained' : 'MBRWithin',    # .. ..

    22         'contains' : 'MBRContains',

    23         'disjoint' : 'MBRDisjoint',

    24         'equals' : 'MBREqual',

    25         'exact' : 'MBREqual',

    26         'intersects' : 'MBRIntersects',

    27         'overlaps' : 'MBROverlaps',

    28         'same_as' : 'MBREqual',

    29         'touches' : 'MBRTouches',

    30         'within' : 'MBRWithin',

    31         }

    32 

    33     gis_terms = dict([(term, None) for term in geometry_functions.keys() + ['isnull']])

    34 

    35     def geo_db_type(self, f):

    36         return f.geom_type

    37 

    38     def get_geom_placeholder(self, value, srid):

    39         """

    40         The placeholder here has to include MySQL's WKT constructor.  Because

    41         MySQL does not support spatial transformations, there is no need to

    42         modify the placeholder based on the contents of the given value.

    43         """

    44         if hasattr(value, 'expression'):

    45             placeholder = '%s.%s' % tuple(map(self.quote_name, value.cols[value.expression]))

    46         else:

    47             placeholder = '%s(%%s)' % self.from_text

    48         return placeholder

    49 

    50     def spatial_lookup_sql(self, lvalue, lookup_type, value, field, qn):

    51         alias, col, db_type = lvalue

    52 

    53         geo_col = '%s.%s' % (qn(alias), qn(col))

    54 

    55         lookup_info = self.geometry_functions.get(lookup_type, False)

    56         if lookup_info:

    57             return "%s(%s, %s)" % (lookup_info, geo_col,

    58                                    self.get_geom_placeholder(value, field.srid))

    59 

    60         # TODO: Is this really necessary? MySQL can't handle NULL geometries

    61         #  in its spatial indexes anyways.

    62         if lookup_type == 'isnull':

    63             return "%s IS %sNULL" % (geo_col, (not value and 'NOT ' or ''))

    64 

    65         raise TypeError("Got invalid lookup_type: %s" % repr(lookup_type))