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Accessing join query results in SQLAlchemy

If I have:

query = db.session.query(Food, Person).filter(Food.id == Person.favourite_food)
for row in db.session.execute(query)
    print row

The output for first print I get is:

(1, u'Alice', 25, u'F', u'z', None, False, 1, u'icecream', 1, None, False)
(5, u'Bob', 38, u'M', u'z', None, False, 3, u'pizza', 1, None, False)

How do I do:

print row.name, row.gender # <-- how do I do this?

The result does not seem to have column names anymore.

Edit: And also is there a way to serialise the query results with just one line, something like

return Response(json.dumps(query.results), mimetype='application/json')
like image 609
Digital Avatar asked Dec 03 '25 13:12

Digital


1 Answers

When you specify

    query(Food, Person)

the resultant rows will be of type sqlalchemy.util._collections.result, and it will have two fields: Food and Person

the Food part can be referenced either by row[0] or row.Food the Person part can be referenced either by row[1] or row.Person

so e.g.

    print(row.Person.name, row.Person.gender) # works
    print(row[1].name, row[1].gender) # also works

if you only wanted particular fields, you could specify them in the query, eg:

    query = (db.session.query(Person.name, Person.gender, Food.name.label('foodname'))
             .filter(Food.id == Person.favourite_food))

and then the object will have 3 fields: name, gender, foodname

    print(row.name, row.gender, row.foodname)
like image 94
Steinwolfe Avatar answered Dec 05 '25 01:12

Steinwolfe



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