Other SQL Clauses
SQLAlchemy ORM also exposes support for other clauses in SQL, such as ORDER BY, GROUP BY, LIMIT, and OFFSET. All of these are supported by this connector:
ORDER BY
The following example sorts by a specified column using the session object's query() method:rs = session.query(MySurvey_Responses).order_by(MySurvey_Responses.Size)
for instance in rs:
print("Id: ", instance.Id)
print("RespondentId: ", instance.RespondentId)
print("ChoiceId: ", instance.ChoiceId)
print("---------")
You can also use the session object's execute() method perform an ORDER BY. For example:
rs = session.execute(MySurvey_Responses_table.select().order_by(MySurvey_Responses_table.c.Size)) for instance in rs:
GROUP BY
The following example uses the session object's query() method to group records with a specified column:rs = session.query(func.count(MySurvey_Responses.Id).label("CustomCount"), MySurvey_Responses.RespondentId).group_by(MySurvey_Responses.RespondentId)
for instance in rs:
print("Count: ", instance.CustomCount)
print("RespondentId: ", instance.RespondentId)
print("---------")
You can also use the session object's execute() method to perform a GROUP BY:
rs = session.execute(MySurvey_Responses_table.select().with_only_columns([func.count(MySurvey_Responses_table.c.Id).label("CustomCount"), MySurvey_Responses_table.c.RespondentId]).group_by(MySurvey_Responses_table.c.RespondentId))
for instance in rs:
LIMIT and OFFSET
The following example uses the session object's query() method to skip the first 100 records and fetch the following 25:rs = session.query(MySurvey_Responses).limit(25).offset(100)
for instance in rs:
print("Id: ", instance.Id)
print("RespondentId: ", instance.RespondentId)
print("ChoiceId: ", instance.ChoiceId)
print("---------")
You can also use the session object's execute() method to set a LIMIT or OFFSET:
rs = session.execute(MySurvey_Responses_table.select().limit(25).offset(100)) for instance in rs: