def build_filter(self, filter_expr, *args, **kwargs):
if isinstance(filter_expr, Q):
return super().build_filter(filter_expr, *args, **kwargs)
if filter_expr[0].startswith('old__'):
alias = 'OLD'
elif filter_expr[0].startswith('new__'):
alias = 'NEW'
else: # pragma: no cover
raise ValueError(
'Filter expression on trigger.Q object must reference'
' old__ or new__')
filter_expr = (filter_expr[0][5:], filter_expr[1])
node, _ = super().build_filter(filter_expr, *args, **kwargs)
self.alias_map[alias] = BaseTable(alias, alias)
for child in node.children:
child.lhs = Col(
alias=alias,
target=child.lhs.target,
output_field=child.lhs.output_field,
)
return node, {alias}
def test_expressions(self):
self.assertEqual(
repr(Case(When(a=1))),
"<Case: CASE WHEN <Q: (AND: ('a', 1))> THEN Value(None), ELSE Value(None)>"
)
self.assertEqual(repr(Col('alias', 'field')), "Col(alias, field)")
self.assertEqual(repr(Date('published', 'exact')),
"Date(published, exact)")
self.assertEqual(repr(DateTime('published', 'exact', utc)),
"DateTime(published, exact, %s)" % utc)
self.assertEqual(repr(F('published')), "F(published)")
self.assertEqual(repr(F('cost') + F('tax')),
"<CombinedExpression: F(cost) + F(tax)>")
self.assertEqual(
repr(ExpressionWrapper(
F('cost') + F('tax'), models.IntegerField())),
"ExpressionWrapper(F(cost) + F(tax))")
self.assertEqual(repr(Func('published', function='TO_CHAR')),
"Func(F(published), function=TO_CHAR)")
self.assertEqual(repr(OrderBy(Value(1))),
'OrderBy(Value(1), descending=False)')
self.assertEqual(repr(Random()), "Random()")
self.assertEqual(repr(RawSQL('table.col', [])),
"RawSQL(table.col, [])")
self.assertEqual(repr(Ref('sum_cost', Sum('cost'))),
"Ref(sum_cost, Sum(F(cost)))")
self.assertEqual(repr(Value(1)), "Value(1)")
def add_select(self, *fields, **kwargs):
"Replaces the `SELECT` columns with the ones provided."
if 'queryset' in kwargs:
queryset = kwargs.pop('queryset')
else:
queryset = self.get_queryset()
queryset.query.default_cols = False
include_pk = kwargs.pop('include_pk', True)
if include_pk:
fields = [self.root_model._meta.pk] + list(fields)
aliases = []
for pair in fields:
if isinstance(pair, (list, tuple)):
model, field = pair
else:
field = pair
model = field.model
queryset, alias = self.add_joins(model, queryset)
aliases.append(Col(alias, field, field))
if aliases:
queryset.query.select = aliases
return queryset
def _create_index_sql(self, model, *, fields=None, **kwargs):
if fields is None or len(fields) != 1 or not hasattr(
fields[0], 'geodetic'):
return super()._create_index_sql(model, fields=fields, **kwargs)
field = fields[0]
expressions = None
opclasses = None
if field.geom_type == 'RASTER':
# For raster fields, wrap index creation SQL statement with ST_ConvexHull.
# Indexes on raster columns are based on the convex hull of the raster.
expressions = Func(Col(None, field),
template=self.rast_index_template)
fields = None
elif field.dim > 2 and not field.geography:
# Use "nd" ops which are fast on multidimensional cases
opclasses = [self.geom_index_ops_nd]
name = kwargs.get('name')
if not name:
name = self._create_index_name(model._meta.db_table,
[field.column], '_id')
return super()._create_index_sql(
model,
fields=fields,
name=name,
using=' USING %s' % self.geom_index_type,
opclasses=opclasses,
expressions=expressions,
)
def get_extra_restriction(self, where_class, alias, remote_alias):
field = self.rel.to._meta.get_field_by_name(self.content_type_field_name)[0]
contenttype_pk = self.get_content_type().pk
cond = where_class()
lookup = field.get_lookup('exact')(Col(remote_alias, field, field), contenttype_pk)
cond.add(lookup, 'AND')
return cond
def get_col(self, alias, output_field=None):
if output_field is None:
output_field = self
if alias != self.model._meta.db_table or output_field != self:
from django.db.models.expressions import Col
return Col(alias, self, output_field)
else:
return self.cached_col
def get_extra_restriction(self, where_class, alias, related_alias):
""" Inject the LanguageConstraint into the join clause. Actual language
will be resolved by the constraint itself.
"""
related_model = self.related_model
return LanguageConstraint(
Col(alias, related_model._meta.get_field('language_code'),
models.CharField()))
def get_select(self):
""" Special case for if we are preparing a count() query """
if self.is_count_qry is True:
col = (Col("__count", None), ("COUNT(*)", []), None)
klass_info = {"model": self.query.model, "select_fields": ["__count"]}
annotations = dict()
return (col,), klass_info, annotations
else:
return super().get_select()
def add_alias_constraints(queryset, alias, **kwargs):
model, alias = alias
clause = queryset.query.where_class()
for lookup, value in kwargs.items():
field_name, lookup = lookup.split('__')
clause.add(
queryset.query.build_lookup(
[lookup], Col(alias, model._meta.get_field(field_name)),
value), AND)
queryset.query.where.add(clause, AND)
def _resolve_ref(self, name):
"""
Gets called when a column reference is accessed via the CTE instance `.col.name`
"""
if name not in self.fields:
raise RuntimeError("No field with name `{}`".format(name))
field = self.fields.get(name)
field.set_attributes_from_name(name)
return Col(self.name, field, output_field=field)
def resolve_ref(name: str, *_: Any, **__: Any) -> 'Col':
from django.db.models.expressions import Col
from django.db.models.fields import Field
# We need to do some faking of the ref resolution.
# This essentially enables us to have a bit more complete
# workings of F().
# An interesting point to raise here is, we need to pass a Field in.
# However, it doesn't need to be the "correct" field. At this point,
# all conversion has been done, so now we just need to get a valid
# target in.
return Col(name, Field())
def add_alias_constraints(queryset, alias, **kwargs):
""" Add constraints to queryset, for given alias.
Bypass high-level API to prevent ORM from creating a new JOIN.
alias - table name or alias to modify; must already be in query
kwargs - Django-style lookup=value conditions.
"""
model, alias = alias
clause = queryset.query.where_class()
for lookup, value in kwargs.items():
field_name, lookup = lookup.split('__')
clause.add(queryset.query.build_lookup(
[lookup],
Col(alias, model._meta.get_field(field_name)),
value
), AND)
queryset.query.where.add(clause, AND)
def as_sql(self, compiler, connection):
""" Generate SQL for the language constraint.
Use the language set by the queryset onto the query object.
Replace None with current language, providing lazy evaluation of language(None)
"""
language = compiler.query.language_code or translation.get_language()
if language == 'all':
assert hasattr(compiler.query.model._meta, 'shared_model')
value = Col(compiler.query.get_initial_alias(),
compiler.query.model._meta.get_field('language_code'),
models.CharField())
else:
value = Value(language)
col_sql, col_params = self.col.as_sql(compiler, connection)
val_sql, val_params = value.as_sql(compiler, connection)
return ('%s = %s' % (col_sql, val_sql), col_params + val_params)
def add_select(self, field_name, lookup_type, order='ASC'):
"""
Converts the query into an extraction query.
"""
try:
field, _, _, joins, _ = self.setup_joins(
field_name.split(LOOKUP_SEP),
self.get_meta(),
self.get_initial_alias(),
)
except FieldError:
raise FieldDoesNotExist("%s has no field named '%s'" %
(self.get_meta().object_name, field_name))
self._check_field(field) # overridden in DateTimeQuery
alias = joins[-1]
select = self._get_select(Col(alias, field), lookup_type)
self.clear_select_clause()
self.select = [SelectInfo(select, None)]
self.distinct = True
self.order_by = [1] if order == 'ASC' else [-1]
if field.null:
self.add_filter(("%s__isnull" % field_name, False))
def get_fields(self, query, keys_only=False):
"""
Get the fields to select, this returns the SELECT -> XXX <- part
This will also popular the 'fieldstrs' field
:return: The list of fields to query, properly quoted, as a string
"""
# Field names to place back into the database
q = query
pk_field = q.get_meta().pk
opts = q.get_meta()
self.pk_col_name = pk_field.column
if q.distinct_fields:
raise Exception("Can't handle distinct_fields yet")
columns_str = []
fields = []
if not self.aggregate_only:
if q.select:
fields = q.select
elif q.default_cols:
fields = [Col('_dummy_', x, x) for x in opts.fields]
# pprint(vars(q))
for col in fields:
field = col.output_field
column = field.column
# Get the document field to select.
if column == pk_field.column:
sel_field = 'META({}).id'.format(
n1ql_escape(BUCKET_PLACEHOLDER))
elif keys_only:
continue
else:
sel_field = n1ql_escape(column)
# See if there's a lookup type.
if hasattr(col, 'lookup_type'):
# pprint(vars(q))
col_alias = self._gen_alias()
selstr, convfld = Transforms.transform(col.lookup_type,
sel_field)
if q.distinct:
self._nopk_where = True
selstr = 'DISTINCT({0})'.format(selstr)
selstr += ' AS ' + col_alias
columns_str.append(selstr)
self.queried_fields.append((col_alias, convfld))
else:
if column == pk_field.column:
columns_str.append(sel_field + ' AS ' + column)
else:
columns_str.append(sel_field)
self.queried_fields.append((column, field))
for alias, annotation in q.annotation_select.items():
colspec = annotation.input_field.value
if not alias:
alias = self._gen_alias()
fn = annotation.function
agstr = '{0}({1}) AS {2}'.format(fn, colspec, n1ql_escape(alias))
self.queried_fields.append((alias, None))
columns_str.append(agstr)
columns_str += self.handle_extra_select(query)
return ','.join(columns_str)
def get_col(self, alias, output_field=None):
output_field = output_field or self.output_field
return Col(alias, self, output_field)
def resolve_expression(self, query=None, *args, **kwargs):
return Col(
alias=self.row_alias,
target=query.model._meta.get_field(self.col_name),
)
def cached_col(self):
from django.db.models.expressions import Col
return Col(self.model._meta.db_table, self)
def __init__(self, alias, target, output_field=None):
super().__init__(alias, target, output_field)
self.children = [Col(alias, key, output_field) for key in target.keys]