Cosmos db provider: Implement owned type null comparison #37321

JoasE · 2025-12-08T14:08:56Z

Comparison used to compare by checking on primary key properties, but this doesn't work for cosmos as it will filter out any document that doesn't contain a property used in a query condition. Compare by IS_NULL(c["Prop"]) OR NOT IS_DEFINED(c["Prop"]) instead. Don't compare document roots as those can't be null. Fixes: #24087

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Comparison used to compare by checking on primary key properties, but this doesn't work for cosmos as it will filter out any document that doesn't contain a property used in a query condition. Compare by c["Prop"] = null instead Fixes: dotnet#24087

…et#24087

Copilot

Pull request overview

Implements correct null/not-null comparison translation for owned types in the Cosmos provider by using IS_NULL(...) OR NOT IS_DEFINED(...) semantics (and avoiding null checks on document roots), and updates/extends query tests accordingly.

Changes:

Update Cosmos structural/entity equality translation to generate IS_NULL/IS_DEFINED checks for null comparisons (and simplify always-true/always-false document-root comparisons).
Add new structural-equality test coverage for optional-nested-owned null/not-null comparisons across providers.
Update Cosmos functional test baselines to reflect the new translation behavior.

Reviewed changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
src/EFCore.Cosmos/Query/Internal/CosmosSqlTranslatingExpressionVisitor.cs	Changes null equality translation to use `IS_NULL`/`IS_DEFINED` and avoids null checks on document roots.
src/EFCore.Cosmos/Query/Internal/CosmosQueryableMethodTranslatingExpressionVisitor.cs	Skips applying predicates that are effectively constant-true (`NOT false`) to avoid redundant filters.
test/EFCore.Specification.Tests/Query/Associations/AssociationsStructuralEqualityTestBase.cs	Adds base tests for optional-associate nested null/not-null scenarios.
test/EFCore.Cosmos.FunctionalTests/Query/Associations/OwnedNavigations/OwnedNavigationsStructuralEqualityCosmosTest.cs	Updates Cosmos assertions to validate new null/not-null SQL translation for owned navigations.
test/EFCore.Cosmos.FunctionalTests/Query/NorthwindMiscellaneousQueryCosmosTest.cs	Updates Cosmos baselines for entity null/not-null comparisons to match new constant folding.
test/EFCore.Sqlite.FunctionalTests/Query/Associations/OwnedTableSplitting/OwnedTableSplittingStructuralEqualitySqliteTest.cs	Adds provider-specific SQL baselines for the new optional-nested null/not-null tests.
test/EFCore.Sqlite.FunctionalTests/Query/Associations/OwnedNavigations/OwnedNavigationsStructuralEqualitySqliteTest.cs	Adds provider-specific SQL baselines for the new optional-nested null/not-null tests.
test/EFCore.Sqlite.FunctionalTests/Query/Associations/OwnedJson/OwnedJsonStructuralEqualitySqliteTest.cs	Adds provider-specific SQL baselines for the new optional-nested null/not-null tests (JSON).
test/EFCore.SqlServer.FunctionalTests/Query/Associations/OwnedTableSplitting/OwnedTableSplittingStructuralEqualitySqlServerTest.cs	Adds provider-specific SQL baselines for the new optional-nested null/not-null tests.
test/EFCore.SqlServer.FunctionalTests/Query/Associations/OwnedNavigations/OwnedNavigationsStructuralEqualitySqlServerTest.cs	Adds provider-specific SQL baselines for the new optional-nested null/not-null tests.
test/EFCore.SqlServer.FunctionalTests/Query/Associations/OwnedJson/OwnedJsonStructuralEqualitySqlServerTest.cs	Adds provider-specific SQL baselines for the new optional-nested null/not-null tests (JSON).
test/EFCore.SqlServer.FunctionalTests/Query/Associations/Navigations/NavigationsStructuralEqualitySqlServerTest.cs	Adds provider-specific SQL baselines for the new optional-nested null/not-null tests (non-owned navigations).
test/EFCore.SqlServer.FunctionalTests/Query/Associations/ComplexTableSplitting/ComplexTableSplittingStructuralEqualitySqlServerTest.cs	Adds provider-specific SQL baselines for the new optional-nested null/not-null tests (complex/table-splitting).
test/EFCore.SqlServer.FunctionalTests/Query/Associations/ComplexJson/ComplexJsonStructuralEqualitySqlServerTest.cs	Adds provider-specific SQL baselines for the new optional-nested null/not-null tests (complex/JSON).

Copilot · 2026-01-29T10:26:17Z

src/EFCore.Cosmos/Query/Internal/CosmosSqlTranslatingExpressionVisitor.cs

-                                ? "!" + nameof(object.Equals)
-                                : "!=",
-                        entityType1.DisplayName()));
+                // Document root can never be be null


Comment typo: "Document root can never be be null" has a duplicated word; please correct to "can never be null".

Suggested change

// Document root can never be be null

// Document root can never be null

Copilot · 2026-01-29T10:26:17Z

src/EFCore.Cosmos/Query/Internal/CosmosSqlTranslatingExpressionVisitor.cs

+        // Null equality
+        if (IsNullSqlConstantExpression(compareReference))
        {
-            var nonNullEntityReference = (IsNullSqlConstantExpression(left) ? rightEntityReference : leftEntityReference)!;
-            var entityType1 = nonNullEntityReference.EntityType;
-            var primaryKeyProperties1 = entityType1.FindPrimaryKey()?.Properties;
-            if (primaryKeyProperties1 == null)
+            if (entityType.IsDocumentRoot() && entityReference.Subquery == null)
            {
-                throw new InvalidOperationException(
-                    CoreStrings.EntityEqualityOnKeylessEntityNotSupported(
-                        nodeType == ExpressionType.Equal
-                            ? equalsMethod ? nameof(object.Equals) : "=="
-                            : equalsMethod
-                                ? "!" + nameof(object.Equals)
-                                : "!=",
-                        entityType1.DisplayName()));
+                // Document root can never be be null
+                result = Visit(Expression.Constant(nodeType != ExpressionType.Equal));
+                return true;
            }

-            result = Visit(
-                primaryKeyProperties1.Select(p =>
-                        Expression.MakeBinary(
-                            nodeType, CreatePropertyAccessExpression(nonNullEntityReference, p),
-                            Expression.Constant(null, p.ClrType.MakeNullable())))
-                    .Aggregate((l, r) => nodeType == ExpressionType.Equal ? Expression.OrElse(l, r) : Expression.AndAlso(l, r)));
+            var isNull = sqlExpressionFactory.Function("IS_NULL", [entityReference.Object], typeof(bool));
+            var isDefined = sqlExpressionFactory.Function("IS_DEFINED", [entityReference.Object], typeof(bool));
+            var notDefined = sqlExpressionFactory.Not(isDefined);
+            var check = sqlExpressionFactory.MakeBinary(ExpressionType.OrElse, isNull, notDefined, typeMappingSource.FindMapping(typeof(bool))) ?? throw new UnreachableException();

+            if (nodeType == ExpressionType.NotEqual)
+            {
+                check = sqlExpressionFactory.Not(check);
+            }
+
+            result = check;
            return true;
        }


Entity equality/null comparison no longer throws for keyless entity types: the keyless check is skipped in the null-comparison branch and only enforced for non-null comparisons. Other providers still throw for entity == null when the entity type is keyless (e.g. RelationalSqlTranslatingExpressionVisitor.StructuralEquality.cs:146-157). If this isn’t intentionally Cosmos-specific, consider preserving the keyless exception behavior here as well to avoid inconsistent semantics across providers.

I thought it was ok to not throw in this case as we are able to easily compare to null the same way we do with keyfull entities. @roji What do you think?

Copilot · 2026-01-29T10:26:17Z

src/EFCore.Cosmos/Query/Internal/CosmosQueryableMethodTranslatingExpressionVisitor.cs

        if (TranslateLambdaExpression(source, predicate) is { } translation)
        {
-            if (translation is not SqlConstantExpression { Value: true })
+            if (translation is not SqlConstantExpression { Value: true } && translation is not SqlUnaryExpression { OperatorType: ExpressionType.Not, Operand: SqlConstantExpression { Value: false } })


This if condition is very long and likely exceeds the repo line-length guideline; please wrap it across multiple lines (and consider extracting the special-case check into a small helper/local to improve readability).

Suggested change

if (translation is not SqlConstantExpression { Value: true } && translation is not SqlUnaryExpression { OperatorType: ExpressionType.Not, Operand: SqlConstantExpression { Value: false } })

static bool IsTriviallyTruePredicate(SqlExpression sqlExpression)

=> sqlExpression is SqlConstantExpression { Value: true }

|| sqlExpression is SqlUnaryExpression

{

OperatorType: ExpressionType.Not,

Operand: SqlConstantExpression { Value: false }

};

if (!IsTriviallyTruePredicate(translation))

Copilot · 2026-01-29T10:26:18Z

...nalTests/Query/Associations/OwnedNavigations/OwnedNavigationsStructuralEqualityCosmosTest.cs

+        AssertSql(
+    """
+SELECT VALUE c
+FROM root c
+WHERE (IS_NULL(c["OptionalAssociate"]) OR NOT(IS_DEFINED(c["OptionalAssociate"])))
+""");


The new AssertSql raw string literals aren’t indented consistently with the rest of the file (e.g. AssertSql( followed by """ at a different indentation). With C# raw string indentation rules, this can accidentally introduce leading whitespace into the expected SQL and make baselines fragile. Please align these """ blocks with the existing pattern used earlier in the file.

JoasE added 4 commits December 8, 2025 15:07

Cleanup

fe40eac

Regenerate NorthwindMiscellaneousQueryCosmosTest and optimize NOT(false)

b3af934

Small cleanup

27fdc25

JoasE marked this pull request as ready for review December 8, 2025 19:25

JoasE requested a review from a team as a code owner December 8, 2025 19:25

JoasE mentioned this pull request Dec 8, 2025

Question on Cosmos DB database provider owned object querying null #24087

Open

AndriySvyryd added the community-contribution label Dec 10, 2025

AndriySvyryd assigned roji Dec 22, 2025

roji force-pushed the main branch 2 times, most recently from 249ae47 to 6b86657 Compare January 13, 2026 17:46

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Merge branch 'main' of https://github.com/dotnet/efcore into fix/dotn…

a2dba87

…et#24087

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Move to IS_NULL OR NOT IS_DEFINED and add test cases that would fail

c294e3b

Copilot AI review requested due to automatic review settings January 29, 2026 10:15

Copilot started reviewing on behalf of JoasE January 29, 2026 10:16 View session

Copilot AI reviewed Jan 29, 2026

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Cosmos db provider: Implement owned type null comparison #37321

Cosmos db provider: Implement owned type null comparison #37321

JoasE commented Dec 8, 2025 •

edited

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	// Document root can never be be null
	// Document root can never be null

-            if (translation is not SqlConstantExpression { Value: true } && translation is not SqlUnaryExpression { OperatorType: ExpressionType.Not, Operand: SqlConstantExpression { Value: false } })
+            static bool IsTriviallyTruePredicate(SqlExpression sqlExpression)
+                => sqlExpression is SqlConstantExpression { Value: true }
+                    || sqlExpression is SqlUnaryExpression
+                    {
+                        OperatorType: ExpressionType.Not,
+                        Operand: SqlConstantExpression { Value: false }
+                    };
+            if (!IsTriviallyTruePredicate(translation))

Cosmos db provider: Implement owned type null comparison #37321

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JoasE commented Dec 8, 2025 •

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