def select(self,query,fields,attributes):
"""
This is the GAE version of select. some notes to consider:
- db['_lastsql'] is not set because there is not SQL statement string
for a GAE query
- 'nativeRef' is a magical fieldname used for self references on GAE
- optional attribute 'projection' when set to True will trigger
use of the GAE projection queries. note that there are rules for
what is accepted imposed by GAE: each field must be indexed,
projection queries cannot contain blob or text fields, and you
cannot use == and also select that same field. see https://developers.google.com/appengine/docs/python/datastore/queries#Query_Projection
- optional attribute 'filterfields' when set to True web2py will only
parse the explicitly listed fields into the Rows object, even though
all fields are returned in the query. This can be used to reduce
memory usage in cases where true projection queries are not
usable.
- optional attribute 'reusecursor' allows use of cursor with queries
that have the limitby attribute. Set the attribute to True for the
first query, set it to the value of db['_lastcursor'] to continue
a previous query. The user must save the cursor value between
requests, and the filters must be identical. It is up to the user
to follow google's limitations: https://developers.google.com/appengine/docs/python/datastore/queries#Query_Cursors
"""
(items, tablename, fields) = self.select_raw(query,fields,attributes)
# self.db['_lastsql'] = self._select(query,fields,attributes)
rows = [[(t==self.db[tablename]._id.name and item) or \
(t=='nativeRef' and item) or getattr(item, t) \
for t in fields] for item in items]
colnames = ['%s.%s' % (tablename, t) for t in fields]
processor = attributes.get('processor',self.parse)
return processor(rows,fields,colnames,False)
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