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Django values_list vs values

People also ask

What is the difference between values and values_list?

"values()" returns a QuerySet of dictionaries. "values_list()" returns a QuerySet of tuples. "values_list()" with "flat=True" returns a QuerySet of values.

How can I filter a Django query with a list of values?

To filter a Python Django query with a list of values, we can use the filter method with in . to search Blog entries with pk set to 1,4 or 7 by calling Blog. objects. filter with the pk_in argument set to [1, 4, 7] .

What does flat true do in Django?

When grabbing a single values from the db, you can pass`flat=true` which will just give you back single values, instead of tuples: >>> queryset = Book. objects.

What is QuerySet in Django?

A QuerySet is a collection of data from a database. A QuerySet is built up as a list of objects. QuerySets makes it easier to get the data you actually need, by allowing you to filter and order the data.


The values() method returns a QuerySet containing dictionaries:

<QuerySet [{'comment_id': 1}, {'comment_id': 2}]>

The values_list() method returns a QuerySet containing tuples:

<QuerySet [(1,), (2,)]>

If you are using values_list() with a single field, you can use flat=True to return a QuerySet of single values instead of 1-tuples:

<QuerySet [1, 2]>

values()

Returns a QuerySet that returns dictionaries, rather than model instances, when used as an iterable.

values_list()

Returns a QuerySet that returns list of tuples, rather than model instances, when used as an iterable.

distinct()

distinct are used to eliminate the duplicate elements.

Example:

>>> list(Article.objects.values_list('id', flat=True)) # flat=True will remove the tuples and return the list   
[1, 2, 3, 4, 5, 6]

>>> list(Article.objects.values('id'))
[{'id':1}, {'id':2}, {'id':3}, {'id':4}, {'id':5}, {'id':6}]

You can get the different values with:

set(Article.objects.values_list('comment_id', flat=True))

The best place to understand the difference is at the official documentation on values / values_list. It has many useful examples and explains it very clearly. The django docs are very user freindly.

Here's a short snippet to keep SO reviewers happy:

values

Returns a QuerySet that returns dictionaries, rather than model instances, when used as an iterable.

And read the section which follows it:

value_list

This is similar to values() except that instead of returning dictionaries, it returns tuples when iterated over.


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