How do I do an OR filter in a Django query

Question

I want to be able to list the items that either a user has added  they are listed as the creator  or the item has been approved   So I basically need to select   item creator   owner or item moderated   False   How would I do this in Django   preferably with a filter or queryset

User · Answer

This might be useful https   docs djangoproject com en dev topics db queries  spanning-multi-valued-relationships  Basically it sounds like they act as OR

User · Answer

There is Q objects that allow to complex lookups  Example   from django db models import Q  Item objects filter Q creator owner    Q moderated False

User · Answer

You can use the   operator to combine querysets directly without needing Q objects   result   Item objects filter item creator   owner    Item objects filter item moderated   False     edit - I was initially unsure if this caused an extra query but  spookylukey pointed out that lazy queryset evaluation takes care of that

User · Answer

Similar to older answers  but a bit simpler  without the lambda  filter kwargs          field a   123       field b  in    3  4  5        To filter these two conditions using OR  Item objects filter Q field a 123    Q field b  in  3  4  5      To get the same result programmatically  list of Q    Q    key  val   for key  val in filter kwargs items    Item objects filter reduce operator or   list of Q     broken in two lines here  for clarity  operator is in standard library  import operator From docstring   or  a  b  -- Same as a   b   For Python3  reduce is not a builtin any more but is still in the standard library  from functools import reduce  P S  Don t forget to make sure list of Q is not empty - reduce   will choke on empty list  it needs at least one element

User · Answer

You want to make filter dynamic then you have to use Lambda like     from django db models import Q  brands     ABC   DEF     GHI    queryset   Product objects filter reduce lambda x  y  x   y   Q brand item  for item in brands      reduce lambda x  y  x   y   Q brand item  for item in brands   is equivalent to  Q brand brands 0     Q brand brands 1     Q brand brands 2

User · Answer

It is worth to note that it s possible to add Q expressions   For example   from django db models import Q  query   Q first name  mark   query add Q email  mark test com    Q OR  query add Q last name  doe    Q AND   queryset   User objects filter query    This ends up with a query like     first name    mark  or email    mark test com   and last name    doe    This way there is no need to deal with or operators  reduce s etc

[django] How do I do an OR filter in a Django query?

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