132
votes

I want a "group by and count" command in sqlalchemy. How can I do this?

3
Seems to be a duplicate of stackoverflow.com/questions/370174/… - Arnkrishn
thanks , thank you vary much - Nazmul Hasan

3 Answers

194
votes

The documentation on counting says that for group_by queries it is better to use func.count():

from sqlalchemy import func
session.query(Table.column, func.count(Table.column)).group_by(Table.column).all()
51
votes

If you are using Table.query property:

from sqlalchemy import func
Table.query.with_entities(Table.column, func.count(Table.column)).group_by(Table.column).all()

If you are using session.query() method (as stated in miniwark's answer):

from sqlalchemy import func
session.query(Table.column, func.count(Table.column)).group_by(Table.column).all()
30
votes

You can also count on multiple groups and their intersection:

self.session.query(func.count(Table.column1),Table.column1, Table.column2).group_by(Table.column1, Table.column2).all()

The query above will return counts for all possible combinations of values from both columns.