def recreate_database():
Song.collection().drop()
Rating.collection().drop()
Song.insert_many(songs_from_json())
Song.collection().create_index([
('artist', TEXT),
('title', TEXT),
])
def songs_avg_rating(song_id):
try:
song_id = bson.ObjectId(song_id)
except InvalidId:
raise NotFound # TODO: should return this also when valid ObjectId, but song with the id doesn't exist
try:
result = next(Rating.collection().aggregate(pipeline=[
{
'$match': {
'song_id': bson.ObjectId(song_id)
},
},
{
'$group': {
'_id': '$song_id',
'average_rating': {
'$avg': '$rating'
},
'min_rating': {
'$min': '$rating'
},
'max_rating': {
'$max': '$rating'
},
},
},
]))
del result['_id']
except StopIteration:
result = dict(
average_rating=None,
min_rating=None,
max_rating=None,
)
return jsonify(result)