1 """

     2 19. OR lookups

     3 

     4 To perform an OR lookup, or a lookup that combines ANDs and ORs,

     5 combine QuerySet objects using & and | operators.

     6 

     7 Alternatively, use positional arguments, and pass one or more expressions

     8 of clauses using the variable ``django.db.models.Q`` (or any object with

     9 a get_sql method).

    10 

    11 

    12 """

    13 

    14 from django.db import models

    15 

    16 class Article(models.Model):

    17     headline = models.CharField(maxlength=50)

    18     pub_date = models.DateTimeField()

    19 

    20     class Meta:

    21        ordering = ('pub_date',)

    22 

    23     def __str__(self):

    24         return self.headline

    25 

    26 __test__ = {'API_TESTS':"""

    27 >>> from datetime import datetime

    28 >>> from django.db.models import Q

    29 

    30 >>> a1 = Article(headline='Hello', pub_date=datetime(2005, 11, 27))

    31 >>> a1.save()

    32 

    33 >>> a2 = Article(headline='Goodbye', pub_date=datetime(2005, 11, 28))

    34 >>> a2.save()

    35 

    36 >>> a3 = Article(headline='Hello and goodbye', pub_date=datetime(2005, 11, 29))

    37 >>> a3.save()

    38 

    39 >>> Article.objects.filter(headline__startswith='Hello') |  Article.objects.filter(headline__startswith='Goodbye')

    40 [<Article: Hello>, <Article: Goodbye>, <Article: Hello and goodbye>]

    41 

    42 >>> Article.objects.filter(Q(headline__startswith='Hello') | Q(headline__startswith='Goodbye'))

    43 [<Article: Hello>, <Article: Goodbye>, <Article: Hello and goodbye>]

    44 

    45 >>> Article.objects.filter(Q(headline__startswith='Hello') & Q(headline__startswith='Goodbye'))

    46 []

    47 

    48 # You can shorten this syntax with code like the following,

    49 # which is especially useful if building the query in stages:

    50 >>> articles = Article.objects.all()

    51 >>> articles.filter(headline__startswith='Hello') & articles.filter(headline__startswith='Goodbye')

    52 []

    53 

    54 >>> articles.filter(headline__startswith='Hello') & articles.filter(headline__contains='bye')

    55 [<Article: Hello and goodbye>]

    56 

    57 >>> Article.objects.filter(Q(headline__contains='bye'), headline__startswith='Hello')

    58 [<Article: Hello and goodbye>]

    59 

    60 >>> Article.objects.filter(headline__contains='Hello') | Article.objects.filter(headline__contains='bye')

    61 [<Article: Hello>, <Article: Goodbye>, <Article: Hello and goodbye>]

    62 

    63 >>> Article.objects.filter(headline__iexact='Hello') | Article.objects.filter(headline__contains='ood')

    64 [<Article: Hello>, <Article: Goodbye>, <Article: Hello and goodbye>]

    65 

    66 >>> Article.objects.filter(Q(pk=1) | Q(pk=2))

    67 [<Article: Hello>, <Article: Goodbye>]

    68 

    69 >>> Article.objects.filter(Q(pk=1) | Q(pk=2) | Q(pk=3))

    70 [<Article: Hello>, <Article: Goodbye>, <Article: Hello and goodbye>]

    71 

    72 # You could also use "in" to accomplish the same as above.

    73 >>> Article.objects.filter(pk__in=[1,2,3])

    74 [<Article: Hello>, <Article: Goodbye>, <Article: Hello and goodbye>]

    75 

    76 >>> Article.objects.filter(pk__in=[1,2,3,4])

    77 [<Article: Hello>, <Article: Goodbye>, <Article: Hello and goodbye>]

    78 

    79 # Passing "in" an empty list returns no results ...

    80 >>> Article.objects.filter(pk__in=[])

    81 []

    82 

    83 # ... but can return results if we OR it with another query.

    84 >>> Article.objects.filter(Q(pk__in=[]) | Q(headline__icontains='goodbye'))

    85 [<Article: Goodbye>, <Article: Hello and goodbye>]

    86 

    87 # Q arg objects are ANDed

    88 >>> Article.objects.filter(Q(headline__startswith='Hello'), Q(headline__contains='bye'))

    89 [<Article: Hello and goodbye>]

    90 

    91 # Q arg AND order is irrelevant

    92 >>> Article.objects.filter(Q(headline__contains='bye'), headline__startswith='Hello')

    93 [<Article: Hello and goodbye>]

    94 

    95 # Try some arg queries with operations other than get_list

    96 >>> Article.objects.get(Q(headline__startswith='Hello'), Q(headline__contains='bye'))

    97 <Article: Hello and goodbye>

    98 

    99 >>> Article.objects.filter(Q(headline__startswith='Hello') | Q(headline__contains='bye')).count()

   100 3

   101 

   102 >>> list(Article.objects.filter(Q(headline__startswith='Hello'), Q(headline__contains='bye')).values())

   103 [{'headline': 'Hello and goodbye', 'pub_date': datetime.datetime(2005, 11, 29, 0, 0), 'id': 3}]

   104 

   105 >>> Article.objects.filter(Q(headline__startswith='Hello')).in_bulk([1,2])

   106 {1: <Article: Hello>}

   107 

   108 # Demonstrating exclude with a Q object

   109 >>> Article.objects.exclude(Q(headline__startswith='Hello'))

   110 [<Article: Goodbye>]

   111 

   112 # The 'complex_filter' method supports framework features such as

   113 # 'limit_choices_to' which normally take a single dictionary of lookup arguments

   114 # but need to support arbitrary queries via Q objects too.

   115 >>> Article.objects.complex_filter({'pk': 1})

   116 [<Article: Hello>]

   117 >>> Article.objects.complex_filter(Q(pk=1) | Q(pk=2))

   118 [<Article: Hello>, <Article: Goodbye>]

   119 """}