Certain aggregate functions can also be used within SQLAlchemy by using the func module. First, you will need to import it:

from sqlalchemy.sql import func

Once imported, the following aggregate functions are available:

COUNT

This example counts the number of records in a set of groups using the session object's query() method.

rs = session.query(func.count(Constituents.Id).label("CustomCount"), Constituents.Id).group_by(Constituents.Id)
for instance in rs:
	print("Count: ", instance.CustomCount)
	print("Id: ", instance.Id)
	print("---------")

Alternatively, you can execute COUNT using the session object's execute() method.

rs = session.execute(Constituents_table.select().with_only_columns([func.count(Constituents_table.c.Id).label("CustomCount"), Constituents_table.c.Id])group_by(Constituents_table.c.Id))
for instance in rs:

SUM

This example calculates the cumulative amount of a numeric column in a set of groups.

rs = session.query(func.sum(Constituents.AnnualRevenue).label("CustomSum"), Constituents.Id).group_by(Constituents.Id)
for instance in rs:
	print("Sum: ", instance.CustomSum)
	print("Id: ", instance.Id)
	print("---------")

Alternatively, you can invoke SUM using the session object's execute() method.

rs = session.execute(Constituents_table.select().with_only_columns([func.sum(Constituents_table.c.AnnualRevenue).label("CustomSum"), Constituents_table.c.Id]).group_by(Constituents_table.c.Id))
for instance in rs:

AVG

This example calculates the average amount of a numeric column in a set of groups using the session object's query() method.

rs = session.query(func.avg(Constituents.AnnualRevenue).label("CustomAvg"), Constituents.Id).group_by(Constituents.Id)
for instance in rs:
	print("Avg: ", instance.CustomAvg)
	print("Id: ", instance.Id)
	print("---------")

Alternatively, you can invoke AVG using the session object's execute() method.

rs = session.execute(Constituents_table.select().with_only_columns([func.avg(Constituents_table.c.AnnualRevenue).label("CustomAvg"), Constituents_table.c.Id]).group_by(Constituents_table.c.Id))
for instance in rs:

MAX and MIN

This example finds the maximum value and minimum value of a numeric column in a set of groups.

rs = session.query(func.max(Constituents.AnnualRevenue).label("CustomMax"), func.min(Constituents.AnnualRevenue).label("CustomMin"), Constituents.Id).group_by(Constituents.Id)
for instance in rs:
	print("Max: ", instance.CustomMax)
	print("Min: ", instance.CustomMin)
	print("Id: ", instance.Id)
	print("---------")

Alternatively, you can invoke MAX and MIN using the session object's execute() method.

rs = session.execute(Constituents_table.select().with_only_columns([func.max(Constituents_table.c.AnnualRevenue).label("CustomMax"), func.min(Constituents_table.c.AnnualRevenue).label("CustomMin"), Constituents_table.c.Id]).group_by(Constituents_table.c.Id))
for instance in rs: