Sqlalchemy: Purpose of .all()

Question

What is the use of .all(). When the following function

def showRestaurants():
restaurants = session.query(Restaurant)
return render_template('restaurant.html',restaurants=restaurants)

Returns the same result as this function

def showRestaurants():
restaurants = session.query(Restaurant).all()
return render_template('restaurant.html',restaurants=restaurants)

For this restaurant.html file

<html>
<body>
<h1> Restaurants </h1>

{% for x in restaurants %}
</br>

{% endfor %}
</body>
</html>

midori · Accepted Answer · 2016-01-27T07:56:38.663

5

First example returns Query object and you can apply additional methods on it, such as all() - it will return results represented by that Query as a list.

Query object works on each row before give it, while the second works on all rows, before starting to give them.

edited Jan 27 '16 at 07:56

answered Jan 27 '16 at 07:50

midori

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Why can I iterate over the query object in the html file. Since both are of different types – Mustafa Khan Jan 27 '16 at 07:53
i added some explanation – midori Jan 27 '16 at 07:56
you can iterate over the object becaus it has __iter__ method – midori Jan 27 '16 at 07:57

score 0 · Answer 2 · edited Sep 17 '22 at 03:37

0

it just executes your query and returns a list with results, see https://docs.sqlalchemy.org/en/rel_1_0/orm/query.html#sqlalchemy.orm.query.Query.all

alternatively you can execute the query manually:

session.execute(Restaurant.select())

edited Sep 17 '22 at 03:37

Matt

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answered Jan 27 '16 at 07:44

Paweł Kordowski

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Sqlalchemy: Purpose of .all()

2 Answers2