Get second row from a SQLAlchemy query
Question:
I can get the first value using myQuery.first(), but I want to get the second row/value. How can I do that?
myQuery = db.session.query(Inquiry).order_by(func.count(Ruling.id).desc()).limit(2)
Answers:
Try to use myQuery[1] to get the second row. After you used your query.
after limit function, use index to find it
myQuery = db.session.query(Inquiry).order_by(func.count(Ruling.id).desc()).limit(2)[1]
This can be accomplished by applying offset to the returned query, and then getting the first() result:
db.session.query(Inquiry).order_by(func.count(Ruling.id).desc()).offset(1).first()
This has the advantage that it doesn’t raise an exception if there are no results – though, you could use one() if you did want an exception in this case.
Edit: I also found that if you need to handle the case where there may not be a previous row, and you want to fallback to the first row, you can do:
db.session.query(Inquiry).order_by(func.count(Ruling.id).desc()).limit(2)[-1]
The [-1] in this case gets you the last element in the list – so if the query returns 2 elements, you get the second element. But if it only returns 1 element, you get that one. Though this would raise an index out of range exception if no elements are returned.
I can get the first value using myQuery.first(), but I want to get the second row/value. How can I do that?
myQuery = db.session.query(Inquiry).order_by(func.count(Ruling.id).desc()).limit(2)
Try to use myQuery[1] to get the second row. After you used your query.
after limit function, use index to find it
myQuery = db.session.query(Inquiry).order_by(func.count(Ruling.id).desc()).limit(2)[1]
This can be accomplished by applying offset to the returned query, and then getting the first() result:
db.session.query(Inquiry).order_by(func.count(Ruling.id).desc()).offset(1).first()
This has the advantage that it doesn’t raise an exception if there are no results – though, you could use one() if you did want an exception in this case.
Edit: I also found that if you need to handle the case where there may not be a previous row, and you want to fallback to the first row, you can do:
db.session.query(Inquiry).order_by(func.count(Ruling.id).desc()).limit(2)[-1]
The [-1] in this case gets you the last element in the list – so if the query returns 2 elements, you get the second element. But if it only returns 1 element, you get that one. Though this would raise an index out of range exception if no elements are returned.