How to use avg and sum in SQLAlchemy query
attention = Attention_scores.query
.with_entities(func.avg(Attention_scores.score))
.filter(classroom_number == classroom_number)
.all()
I tried it like this and it gave the correct average.
You should use something like:
from sqlalchemy.sql import func
session.query(func.avg(Rating.field2).label('average')).filter(Rating.url==url_string.netloc)
You cannot use MyObject.query
here, because SqlAlchemy tries to find a field to put result of avg
function to, and it fails.
You cannot use MyObject.query here, because SqlAlchemy tries to find a field to put result of avg function to, and it fails.
This isn't exactly true. func.avg(Rating.field2).label('average')
returns a Column
object (the same type object that it was given to be precise). So you can use it with the with_entities
method of the query object.
This is how you would do it for your example:
Rating.query.with_entities(func.avg(Rating.field2).label('average')).filter(Rating.url == url_string.netloc)