online-judge/judge/fulltext.py
2019-09-28 20:53:49 -04:00

56 lines
2.0 KiB
Python

# From: http://www.mercurytide.co.uk/news/article/django-full-text-search/
from django.db import connection, models
from django.db.models.query import QuerySet
class SearchQuerySet(QuerySet):
DEFAULT = ''
BOOLEAN = ' IN BOOLEAN MODE'
NATURAL_LANGUAGE = ' IN NATURAL LANGUAGE MODE'
QUERY_EXPANSION = ' WITH QUERY EXPANSION'
def __init__(self, fields=None, **kwargs):
super(SearchQuerySet, self).__init__(**kwargs)
self._search_fields = fields
def _clone(self, *args, **kwargs):
queryset = super(SearchQuerySet, self)._clone(*args, **kwargs)
queryset._search_fields = self._search_fields
return queryset
def search(self, query, mode=DEFAULT):
meta = self.model._meta
# Get the table name and column names from the model
# in `table_name`.`column_name` style
columns = [meta.get_field(name).column for name in self._search_fields]
full_names = ['%s.%s' %
(connection.ops.quote_name(meta.db_table),
connection.ops.quote_name(column))
for column in columns]
# Create the MATCH...AGAINST expressions
fulltext_columns = ', '.join(full_names)
match_expr = ('MATCH(%s) AGAINST (%%s%s)' % (fulltext_columns, mode))
# Add the extra SELECT and WHERE options
return self.extra(select={'relevance': match_expr},
select_params=[query],
where=[match_expr],
params=[query])
class SearchManager(models.Manager):
def __init__(self, fields=None):
super(SearchManager, self).__init__()
self._search_fields = fields
def get_queryset(self):
if self._search_fields is not None:
return SearchQuerySet(model=self.model, fields=self._search_fields)
return super(SearchManager, self).get_queryset()
def search(self, *args, **kwargs):
return self.get_queryset().search(*args, **kwargs)