refactor query generation

fixes #13, #22

Co-authored-by: Tim Graham <[email protected]>

.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