refactor query generation

fixes #13, #22 Co-authored-by: Tim Graham <timograham@gmail.com>

Author: WaVEV

.github/workflows/test-python.yml

@@ -80,6 +80,7 @@ jobs:
  lookup
  model_fields
  or_lookups
+ queries.tests.Ticket12807Tests.test_ticket_12807
  sessions_tests
  timezones
  update

django_mongodb/__init__.py

@@ -5,3 +5,13 @@
 from .utils import check_django_compatability
 
 check_django_compatability()
+
+from .expressions import register_expressions # noqa: E402
+from .functions import register_functions # noqa: E402
+from .lookups import register_lookups # noqa: E402
+from .query import register_nodes # noqa: E402
+
+register_expressions()
+register_functions()
+register_lookups()
+register_nodes()

django_mongodb/base.py

@@ -1,3 +1,5 @@
+import re
+
 from django.core.exceptions import ImproperlyConfigured
 from django.db.backends.base.base import BaseDatabaseWrapper
 from django.db.backends.signals import connection_created
@@ -10,6 +12,7 @@
 from .features import DatabaseFeatures
 from .introspection import DatabaseIntrospection
 from .operations import DatabaseOperations
+from .query_utils import safe_regex
 from .schema import DatabaseSchemaEditor
 from .utils import CollectionDebugWrapper
 
@@ -52,11 +55,23 @@ class DatabaseWrapper(BaseDatabaseWrapper):
  "UUIDField": "string",
  }
  operators = {
- "exact": "= %s",
- "gt": "> %s",
- "gte": ">= %s",
- "lt": "< %s",
- "lte": "<= %s",
+ "exact": lambda val: val,
+ "gt": lambda val: {"$gt": val},
+ "gte": lambda val: {"$gte": val},
+ "lt": lambda val: {"$lt": val},
+ "lte": lambda val: {"$lte": val},
+ "in": lambda val: {"$in": val},
+ "range": lambda val: {"$gte": val[0], "$lte": val[1]},
+ "isnull": lambda val: None if val else {"$ne": None},
+ "iexact": safe_regex("^%s$", re.IGNORECASE),
+ "startswith": safe_regex("^%s"),
+ "istartswith": safe_regex("^%s", re.IGNORECASE),
+ "endswith": safe_regex("%s$"),
+ "iendswith": safe_regex("%s$", re.IGNORECASE),
+ "contains": safe_regex("%s"),
+ "icontains": safe_regex("%s", re.IGNORECASE),
+ "regex": lambda val: re.compile(val),
+ "iregex": lambda val: re.compile(val, re.IGNORECASE),
  }
 
  display_name = "MongoDB"

django_mongodb/compiler.py

@@ -1,4 +1,4 @@
-from django.core.exceptions import EmptyResultSet
+from django.core.exceptions import EmptyResultSet, FullResultSet
 from django.db import DatabaseError, IntegrityError, NotSupportedError
 from django.db.models import NOT_PROVIDED, Count, Expression, Value
 from django.db.models.aggregates import Aggregate
@@ -136,7 +136,10 @@ def build_query(self, columns=None):
  self.check_query()
  self.setup_query()
  query = self.query_class(self, columns)
- query.add_filters(self.query.where)
+ try:
+ query.mongo_query = self.query.where.as_mql(self, self.connection)
+ except FullResultSet:
+ query.mongo_query = {}
  query.order_by(self._get_ordering())
  return query
 

django_mongodb/expressions.py

@@ -0,0 +1,9 @@
+from django.db.models.expressions import Col
+
+
+def col(self, compiler, connection): # noqa: ARG001
+ return self.target.column
+
+
+def register_expressions():
+ Col.as_mql = col

django_mongodb/features.py

@@ -16,11 +16,10 @@ class DatabaseFeatures(BaseDatabaseFeatures):
  # cannot encode object: <django.db.models.expressions.DatabaseDefault
  "basic.tests.ModelInstanceCreationTests.test_save_primary_with_db_default",
  # Date lookups aren't implemented: https://github.com/mongodb-labs/django-mongodb/issues/9
- # (e.g. 'ExtractMonth' object has no attribute 'alias')
+ # (e.g. ExtractWeekDay is not supported.)
  "basic.tests.ModelLookupTest.test_does_not_exist",
  "basic.tests.ModelLookupTest.test_equal_lookup",
  "basic.tests.ModelLookupTest.test_rich_lookup",
- "basic.tests.ModelLookupTest.test_too_many",
  "basic.tests.ModelTest.test_year_lookup_edge_case",
  "lookup.tests.LookupTests.test_chain_date_time_lookups",
  "lookup.test_timefield.TimeFieldLookupTests.test_hour_lookups",
@@ -30,29 +29,25 @@ class DatabaseFeatures(BaseDatabaseFeatures):
  "timezones.tests.NewDatabaseTests.test_query_convert_timezones",
  "timezones.tests.NewDatabaseTests.test_query_datetime_lookups",
  "timezones.tests.NewDatabaseTests.test_query_datetime_lookups_in_other_timezone",
- # 'NulledTransform' object has no attribute 'alias'
+ # 'NulledTransform' object has no attribute 'as_mql'.
  "lookup.tests.LookupTests.test_exact_none_transform",
  # "Save with update_fields did not affect any rows."
  "basic.tests.SelectOnSaveTests.test_select_on_save_lying_update",
  # filtering on large decimalfield, see https://code.djangoproject.com/ticket/34590
  # for some background.
  "model_fields.test_decimalfield.DecimalFieldTests.test_lookup_decimal_larger_than_max_digits",
  "model_fields.test_decimalfield.DecimalFieldTests.test_lookup_really_big_value",
- # 'TruncDate' object has no attribute 'alias'
+ # 'TruncDate' object has no attribute 'as_mql'.
  "model_fields.test_datetimefield.DateTimeFieldTests.test_lookup_date_with_use_tz",
  "model_fields.test_datetimefield.DateTimeFieldTests.test_lookup_date_without_use_tz",
- # Incorrect empty QuerySet handling: https://github.com/mongodb-labs/django-mongodb/issues/22
- "lookup.tests.LookupTests.test_in",
- "or_lookups.tests.OrLookupsTests.test_empty_in",
  # Slicing with QuerySet.count() doesn't work.
  "lookup.tests.LookupTests.test_count",
- # Custom lookups not supported.
- "lookup.tests.LookupTests.test_custom_lookup_none_rhs",
- # Lookup in order_by() not supported: argument of type 'LessThan' is not iterable
+ # Lookup in order_by() not supported:
+ # unsupported operand type(s) for %: 'function' and 'str'
  "lookup.tests.LookupQueryingTests.test_lookup_in_order_by",
  # annotate() after values() doesn't raise NotSupportedError.
  "lookup.tests.LookupTests.test_exact_query_rhs_with_selected_columns",
- # tuple index out of range in _normalize_lookup_value()
+ # tuple index out of range in process_rhs()
  "lookup.tests.LookupTests.test_exact_sliced_queryset_limit_one",
  "lookup.tests.LookupTests.test_exact_sliced_queryset_limit_one_offset",
  # Regex lookup doesn't work on non-string fields.

django_mongodb/functions.py

@@ -0,0 +1,24 @@
+from django.db import NotSupportedError
+from django.db.models.expressions import Col
+from django.db.models.functions.datetime import Extract
+
+from .query_utils import process_lhs
+
+
+def extract(self, compiler, connection):
+ lhs_mql = process_lhs(self, compiler, connection)
+ if self.lookup_name == "week":
+ operator = "$week"
+ elif self.lookup_name == "month":
+ operator = "$month"
+ elif self.lookup_name == "year":
+ operator = "$year"
+ else:
+ raise NotSupportedError("%s is not supported." % self.__class__.__name__)
+ if isinstance(self.lhs, Col):
+ lhs_mql = f"${lhs_mql}"
+ return {operator: lhs_mql}
+
+
+def register_functions():
+ Extract.as_mql = extract

django_mongodb/lookups.py

@@ -0,0 +1,47 @@
+from django.db import NotSupportedError
+from django.db.models.expressions import Col
+from django.db.models.fields.related_lookups import In, MultiColSource, RelatedIn
+from django.db.models.lookups import BuiltinLookup, Exact, IsNull, UUIDTextMixin
+
+from .query_utils import process_lhs, process_rhs
+
+
+def builtin_lookup(self, compiler, connection):
+ lhs_mql = process_lhs(self, compiler, connection)
+ value = process_rhs(self, compiler, connection)
+ rhs_mql = connection.operators[self.lookup_name](value)
+ return {lhs_mql: rhs_mql}
+
+
+def exact(self, compiler, connection):
+ lhs_mql = process_lhs(self, compiler, connection)
+ value = process_rhs(self, compiler, connection)
+ if isinstance(self.lhs, Col):
+ lhs_mql = f"${lhs_mql}"
+ return {"$expr": {"$eq": [lhs_mql, value]}}
+
+
+def in_(self, compiler, connection):
+ if isinstance(self.lhs, MultiColSource):
+ raise NotImplementedError("MultiColSource is not supported.")
+ return builtin_lookup(self, compiler, connection)
+
+
+def is_null(self, compiler, connection):
+ if not isinstance(self.rhs, bool):
+ raise ValueError("The QuerySet value for an isnull lookup must be True or False.")
+ lhs_mql = process_lhs(self, compiler, connection)
+ rhs_mql = connection.operators["isnull"](self.rhs)
+ return {lhs_mql: rhs_mql}
+
+
+def uuid_text_mixin(self, compiler, connection): # noqa: ARG001
+ raise NotSupportedError("Pattern lookups on UUIDField are not supported.")
+
+
+def register_lookups():
+ BuiltinLookup.as_mql = builtin_lookup
+ Exact.as_mql = exact
+ In.as_mql = RelatedIn.as_mql = in_
+ IsNull.as_mql = is_null
+ UUIDTextMixin.as_mql = uuid_text_mixin