Commit 65246de7 authored by Michał Modzelewski's avatar Michał Modzelewski Committed by Tim Graham
Browse files

Fixed #24031 -- Added CASE expressions to the ORM.

parent aa8ee6a5

AUTHORS

+1 −0
Original line number Diff line number Diff line
@@ -475,6 +475,7 @@ answer newbie questions, and generally made Django that much better: 
    Michael Thornhill <michael.thornhill@gmail.com>

    Michal Chruszcz <troll@pld-linux.org>

    michal@plovarna.cz

    Michał Modzelewski <michal.modzelewski@gmail.com>

    Mihai Damian <yang_damian@yahoo.com>

    Mihai Preda <mihai_preda@yahoo.com>

    Mikaël Barbero <mikael.barbero nospam at nospam free.fr>

django/db/backends/__init__.py

+8 −0
Original line number Diff line number Diff line
@@ -821,6 +821,14 @@ class BaseDatabaseOperations(object): 
        """

        return "SELECT cache_key FROM %s ORDER BY cache_key LIMIT 1 OFFSET %%s"



    def unification_cast_sql(self, output_field):

        """

        Given a field instance, returns the SQL necessary to cast the result of

        a union to that type. Note that the resulting string should contain a

        '%s' placeholder for the expression being cast.

        """

        return '%s'



    def date_extract_sql(self, lookup_type, field_name):

        """

        Given a lookup_type of 'year', 'month' or 'day', returns the SQL that

django/db/backends/postgresql_psycopg2/operations.py

+12 −0
Original line number Diff line number Diff line
@@ -5,6 +5,18 @@ from django.db.backends import BaseDatabaseOperations 




class DatabaseOperations(BaseDatabaseOperations):

    def unification_cast_sql(self, output_field):

        internal_type = output_field.get_internal_type()

        if internal_type in ("GenericIPAddressField", "IPAddressField", "TimeField", "UUIDField"):

            # PostgreSQL will resolve a union as type 'text' if input types are

            # 'unknown'.

            # http://www.postgresql.org/docs/9.4/static/typeconv-union-case.html

            # These fields cannot be implicitly cast back in the default

            # PostgreSQL configuration so we need to explicitly cast them.

            # We must also remove components of the type within brackets:

            # varchar(255) -> varchar.

            return 'CAST(%%s AS %s)' % output_field.db_type(self.connection).split('(')[0]

        return '%s'



    def date_extract_sql(self, lookup_type, field_name):

        # http://www.postgresql.org/docs/current/static/functions-datetime.html#FUNCTIONS-DATETIME-EXTRACT

django/db/models/__init__.py

+1 −1
Original line number Diff line number Diff line
@@ -4,7 +4,7 @@ import warnings 


from django.core.exceptions import ObjectDoesNotExist, ImproperlyConfigured  # NOQA

from django.db.models.query import Q, QuerySet, Prefetch  # NOQA

from django.db.models.expressions import ExpressionNode, F, Value, Func  # NOQA

from django.db.models.expressions import ExpressionNode, F, Value, Func, Case, When  # NOQA

from django.db.models.manager import Manager  # NOQA

from django.db.models.base import Model  # NOQA

from django.db.models.aggregates import *  # NOQA

django/db/models/aggregates.py

+2 −2
Original line number Diff line number Diff line
@@ -14,8 +14,9 @@ class Aggregate(Func): 
    contains_aggregate = True

    name = None



    def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False):

    def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):

        assert len(self.source_expressions) == 1

        # Aggregates are not allowed in UPDATE queries, so ignore for_save

        c = super(Aggregate, self).resolve_expression(query, allow_joins, reuse, summarize)

        if c.source_expressions[0].contains_aggregate and not summarize:

            name = self.source_expressions[0].name
@@ -101,7 +102,6 @@ class Count(Aggregate): 
    def __init__(self, expression, distinct=False, **extra):

        if expression == '*':

            expression = Value(expression)

            expression._output_field = IntegerField()

        super(Count, self).__init__(

            expression, distinct='DISTINCT ' if distinct else '', output_field=IntegerField(), **extra)