Python query.Query方法代码示例

# 需要导入模块: from django.db.models.sql import query [as 别名]
# 或者: from django.db.models.sql.query import Query [as 别名]
def __init__(self, lhs, rhs):
        self.lhs, self.rhs = lhs, rhs
        self.rhs = self.get_prep_lookup()
        if hasattr(self.lhs, 'get_bilateral_transforms'):
            bilateral_transforms = self.lhs.get_bilateral_transforms()
        else:
            bilateral_transforms = []
        if bilateral_transforms:
            # Warn the user as soon as possible if they are trying to apply
            # a bilateral transformation on a nested QuerySet: that won't work.
            from django.db.models.sql.query import Query  # avoid circular import
            if isinstance(rhs, Query):
                raise NotImplementedError("Bilateral transformations on nested querysets are not supported.")
        self.bilateral_transforms = bilateral_transforms 

# 需要导入模块: from django.db.models.sql import query [as 别名]
# 或者: from django.db.models.sql.query import Query [as 别名]
def process_rhs(self, compiler, connection):
        from django.db.models.sql.query import Query
        if isinstance(self.rhs, Query):
            if self.rhs.has_limit_one():
                # The subquery must select only the pk.
                self.rhs.clear_select_clause()
                self.rhs.add_fields(['pk'])
            else:
                raise ValueError(
                    'The QuerySet value for an exact lookup must be limited to '
                    'one result using slicing.'
                )
        return super().process_rhs(compiler, connection) 

# 需要导入模块: from django.db.models.sql import query [as 别名]
# 或者: from django.db.models.sql.query import Query [as 别名]
def pre_sql_setup(self):
        """
        If the update depends on results from other tables, munge the "where"
        conditions to match the format required for (portable) SQL updates.

        If multiple updates are required, pull out the id values to update at
        this point so that they don't change as a result of the progressive
        updates.
        """
        refcounts_before = self.query.alias_refcount.copy()
        # Ensure base table is in the query
        self.query.get_initial_alias()
        count = self.query.count_active_tables()
        if not self.query.related_updates and count == 1:
            return
        query = self.query.chain(klass=Query)
        query.select_related = False
        query.clear_ordering(True)
        query._extra = {}
        query.select = []
        query.add_fields([query.get_meta().pk.name])
        super().pre_sql_setup()

        must_pre_select = count > 1 and not self.connection.features.update_can_self_select

        # Now we adjust the current query: reset the where clause and get rid
        # of all the tables we don't need (since they're in the sub-select).
        self.query.where = self.query.where_class()
        if self.query.related_updates or must_pre_select:
            # Either we're using the idents in multiple update queries (so
            # don't want them to change), or the db backend doesn't support
            # selecting from the updating table (e.g. MySQL).
            idents = []
            for rows in query.get_compiler(self.using).execute_sql(MULTI):
                idents.extend(r[0] for r in rows)
            self.query.add_filter(('pk__in', idents))
            self.query.related_ids = idents
        else:
            # The fast path. Filters and updates in one query.
            self.query.add_filter(('pk__in', query))
        self.query.reset_refcounts(refcounts_before) 

# 需要导入模块: from django.db.models.sql import query [as 别名]
# 或者: from django.db.models.sql.query import Query [as 别名]
def __init__(self, lhs, rhs):
        self.lhs, self.rhs = lhs, rhs
        self.rhs = self.get_prep_lookup()
        if hasattr(self.lhs, 'get_bilateral_transforms'):
            bilateral_transforms = self.lhs.get_bilateral_transforms()
        else:
            bilateral_transforms = []
        if bilateral_transforms:
            # Warn the user as soon as possible if they are trying to apply
            # a bilateral transformation on a nested QuerySet: that won't work.
            from django.db.models.sql.query import Query  # avoid circular import
            if isinstance(rhs, Query):
                raise NotImplementedError("Bilateral transformations on nested querysets are not implemented.")
        self.bilateral_transforms = bilateral_transforms 

# 需要导入模块: from django.db.models.sql import query [as 别名]
# 或者: from django.db.models.sql.query import Query [as 别名]
def clone(self, *args, **kwargs):
        _clone = super(VersionedQuery, self).clone(*args, **kwargs)
        try:
            _clone.querytime = self.querytime
        except AttributeError:
            # If the caller is using clone to create a different type of Query,
            # that's OK.
            # An example of this is when creating or updating an object, this
            # method is called with a first parameter of sql.UpdateQuery.
            pass
        return _clone 

# 需要导入模块: from django.db.models.sql import query [as 别名]
# 或者: from django.db.models.sql.query import Query [as 别名]
def test_simple_query(self):
        query = Query(Author)
        where = query.build_where(Q(num__gt=2))
        lookup = where.children[0]
        self.assertIsInstance(lookup, GreaterThan)
        self.assertEqual(lookup.rhs, 2)
        self.assertEqual(lookup.lhs.target, Author._meta.get_field('num')) 

# 需要导入模块: from django.db.models.sql import query [as 别名]
# 或者: from django.db.models.sql.query import Query [as 别名]
def test_complex_query(self):
        query = Query(Author)
        where = query.build_where(Q(num__gt=2) | Q(num__lt=0))
        self.assertEqual(where.connector, OR)

        lookup = where.children[0]
        self.assertIsInstance(lookup, GreaterThan)
        self.assertEqual(lookup.rhs, 2)
        self.assertEqual(lookup.lhs.target, Author._meta.get_field('num'))

        lookup = where.children[1]
        self.assertIsInstance(lookup, LessThan)
        self.assertEqual(lookup.rhs, 0)
        self.assertEqual(lookup.lhs.target, Author._meta.get_field('num')) 

# 需要导入模块: from django.db.models.sql import query [as 别名]
# 或者: from django.db.models.sql.query import Query [as 别名]
def test_multiple_fields(self):
        query = Query(Item)
        where = query.build_where(Q(modified__gt=F('created')))
        lookup = where.children[0]
        self.assertIsInstance(lookup, GreaterThan)
        self.assertIsInstance(lookup.rhs, SimpleCol)
        self.assertIsInstance(lookup.lhs, SimpleCol)
        self.assertEqual(lookup.rhs.target, Item._meta.get_field('created'))
        self.assertEqual(lookup.lhs.target, Item._meta.get_field('modified')) 

# 需要导入模块: from django.db.models.sql import query [as 别名]
# 或者: from django.db.models.sql.query import Query [as 别名]
def test_transform(self):
        query = Query(Author)
        with register_lookup(CharField, Lower):
            where = query.build_where(~Q(name__lower='foo'))
        lookup = where.children[0]
        self.assertIsInstance(lookup, Exact)
        self.assertIsInstance(lookup.lhs, Lower)
        self.assertIsInstance(lookup.lhs.lhs, SimpleCol)
        self.assertEqual(lookup.lhs.lhs.target, Author._meta.get_field('name')) 

# 需要导入模块: from django.db.models.sql import query [as 别名]
# 或者: from django.db.models.sql.query import Query [as 别名]
def test_negated_nullable(self):
        query = Query(Item)
        where = query.build_where(~Q(modified__lt=datetime(2017, 1, 1)))
        self.assertTrue(where.negated)
        lookup = where.children[0]
        self.assertIsInstance(lookup, LessThan)
        self.assertEqual(lookup.lhs.target, Item._meta.get_field('modified'))
        lookup = where.children[1]
        self.assertIsInstance(lookup, IsNull)
        self.assertEqual(lookup.lhs.target, Item._meta.get_field('modified')) 

# 需要导入模块: from django.db.models.sql import query [as 别名]
# 或者: from django.db.models.sql.query import Query [as 别名]
def test_foreign_key_f(self):
        query = Query(Ranking)
        with self.assertRaises(FieldError):
            query.build_where(Q(rank__gt=F('author__num'))) 

# 需要导入模块: from django.db.models.sql import query [as 别名]
# 或者: from django.db.models.sql.query import Query [as 别名]
def test_foreign_key_exclusive(self):
        query = Query(ObjectC)
        where = query.build_where(Q(objecta=None) | Q(objectb=None))
        a_isnull = where.children[0]
        self.assertIsInstance(a_isnull, RelatedIsNull)
        self.assertIsInstance(a_isnull.lhs, SimpleCol)
        self.assertEqual(a_isnull.lhs.target, ObjectC._meta.get_field('objecta'))
        b_isnull = where.children[1]
        self.assertIsInstance(b_isnull, RelatedIsNull)
        self.assertIsInstance(b_isnull.lhs, SimpleCol)
        self.assertEqual(b_isnull.lhs.target, ObjectC._meta.get_field('objectb')) 

# 需要导入模块: from django.db.models.sql import query [as 别名]
# 或者: from django.db.models.sql.query import Query [as 别名]
def resolve_lookup_into_field(self, model_cls: Type[Model], lookup: str) -> Union[Field, ForeignObjectRel]:
        query = Query(model_cls)
        lookup_parts, field_parts, is_expression = query.solve_lookup_type(lookup)
        if lookup_parts:
            raise LookupsAreUnsupported()

        return self._resolve_field_from_parts(field_parts, model_cls) 

# 需要导入模块: from django.db.models.sql import query [as 别名]
# 或者: from django.db.models.sql.query import Query [as 别名]
def pre_sql_setup(self):
        """
        If the update depends on results from other tables, we need to do some
        munging of the "where" conditions to match the format required for
        (portable) SQL updates. That is done here.

        Further, if we are going to be running multiple updates, we pull out
        the id values to update at this point so that they don't change as a
        result of the progressive updates.
        """
        refcounts_before = self.query.alias_refcount.copy()
        # Ensure base table is in the query
        self.query.get_initial_alias()
        count = self.query.count_active_tables()
        if not self.query.related_updates and count == 1:
            return
        query = self.query.clone(klass=Query)
        query.select_related = False
        query.clear_ordering(True)
        query._extra = {}
        query.select = []
        query.add_fields([query.get_meta().pk.name])
        super(SQLUpdateCompiler, self).pre_sql_setup()

        must_pre_select = count > 1 and not self.connection.features.update_can_self_select

        # Now we adjust the current query: reset the where clause and get rid
        # of all the tables we don't need (since they're in the sub-select).
        self.query.where = self.query.where_class()
        if self.query.related_updates or must_pre_select:
            # Either we're using the idents in multiple update queries (so
            # don't want them to change), or the db backend doesn't support
            # selecting from the updating table (e.g. MySQL).
            idents = []
            for rows in query.get_compiler(self.using).execute_sql(MULTI):
                idents.extend(r[0] for r in rows)
            self.query.add_filter(('pk__in', idents))
            self.query.related_ids = idents
        else:
            # The fast path. Filters and updates in one query.
            self.query.add_filter(('pk__in', query))
        self.query.reset_refcounts(refcounts_before) 

# 需要导入模块: from django.db.models.sql import query [as 别名]
# 或者: from django.db.models.sql.query import Query [as 别名]
def pre_sql_setup(self):
        """
        If the update depends on results from other tables, we need to do some
        munging of the "where" conditions to match the format required for
        (portable) SQL updates. That is done here.

        Further, if we are going to be running multiple updates, we pull out
        the id values to update at this point so that they don't change as a
        result of the progressive updates.
        """
        self.query.select_related = False
        self.query.clear_ordering(True)
        super(SQLUpdateCompiler, self).pre_sql_setup()
        count = self.query.count_active_tables()
        if not self.query.related_updates and count == 1:
            return

        # We need to use a sub-select in the where clause to filter on things
        # from other tables.
        query = self.query.clone(klass=Query)
        query.bump_prefix()
        query.extra = {}
        query.select = []
        query.add_fields([query.model._meta.pk.name])
        # Recheck the count - it is possible that fiddling with the select
        # fields above removes tables from the query. Refs #18304.
        count = query.count_active_tables()
        if not self.query.related_updates and count == 1:
            return

        must_pre_select = count > 1 and not self.connection.features.update_can_self_select

        # Now we adjust the current query: reset the where clause and get rid
        # of all the tables we don't need (since they're in the sub-select).
        self.query.where = self.query.where_class()
        if self.query.related_updates or must_pre_select:
            # Either we're using the idents in multiple update queries (so
            # don't want them to change), or the db backend doesn't support
            # selecting from the updating table (e.g. MySQL).
            idents = []
            for rows in query.get_compiler(self.using).execute_sql(MULTI):
                idents.extend([r[0] for r in rows])
            self.query.add_filter(('pk__in', idents))
            self.query.related_ids = idents
        else:
            # The fast path. Filters and updates in one query.
            self.query.add_filter(('pk__in', query))
        for alias in self.query.tables[1:]:
            self.query.alias_refcount[alias] = 0