from django.db.backends.mysql.base import DatabaseOperations
from django.contrib.gis.db.backends.adapter import WKTAdapter
from django.contrib.gis.db.backends.base import BaseSpatialOperations
class MySQLOperations(DatabaseOperations, BaseSpatialOperations):
compiler_module = 'django.contrib.gis.db.models.sql.compiler'
mysql = True
name = 'mysql'
select = 'AsText(%s)'
from_wkb = 'GeomFromWKB'
from_text = 'GeomFromText'
Adapter = WKTAdapter
geometry_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',
}
gis_terms = dict([(term, None) for term in geometry_functions.keys() + ['isnull']])
def geo_db_type(self, f):
return f.geom_type
def get_geom_placeholder(self, value, srid):
"""
The placeholder here has to include MySQL's WKT constructor. Because
MySQL does not support spatial transformations, there is no need to
modify the placeholder based on the contents of the given value.
"""
if hasattr(value, 'expression'):
placeholder = '%s.%s' % tuple(map(self.quote_name, value.cols[value.expression]))
else:
placeholder = '%s(%%s)' % self.from_text
return placeholder
def spatial_lookup_sql(self, lvalue, lookup_type, value, field, qn):
alias, col, db_type = lvalue
geo_col = '%s.%s' % (qn(alias), qn(col))
lookup_info = self.geometry_functions.get(lookup_type, False)
if lookup_info:
return "%s(%s, %s)" % (lookup_info, geo_col,
self.get_geom_placeholder(value, field.srid))
# TODO: Is this really necessary? MySQL can't handle NULL geometries
# in its spatial indexes anyways.
if lookup_type == 'isnull':
return "%s IS %sNULL" % (geo_col, (not value and 'NOT ' or ''))
raise TypeError("Got invalid lookup_type: %s" % repr(lookup_type))
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